理工C

考试试题

[多选题]共用题干 第三篇Listening Device Provides Early Landslide(山崩;地滑;塌方)WarningA device that provides early warning of a landslide by monitoring vibrations(振动)in soil is being tested by UK researchers,The device could save thousands of lives each year by warning when an area should be evacuated(疏散,撤走),the scientists say. Such natural disasters are common in countries that experience sudden, heavy rainfall (降雨,降雨量), and can also be triggered by earthquakes and even watererosion(腐蚀,侵蚀).Landslides start when a few particles of soil or rock within a slope start to move,hut the early stages can be hard to spot.Following this initial movement,"slopes can become unstable in a matter of hours or minutes,"says Nell Dixon at Southborough University,UK. He says。warning system that monitors this movement"might be enough to evacuate a block of flats or clear a road,and save lives".The most common way to monitor a slope for signs of an imminent(即将发生的) landslide is to watch for changes in its shape. Surveyors can do this by measuring aside directly,or sensors(传感器)sunk into boreholes(钻孔,井眼)or fixed above ground can be used to monitor the shape of a slope. Slopes can, however,change shape without triggering a landslide,so either method is prone to causing false alarms.Now Dixon's team has developed a device that listens for the vibrations caused when particles begin movingwithin a slope.The device takes the form of a steel pipe dropped into a borehole in a slope.The borehole is filled in with gravel(砾,沙砾,砾石)around the pipe to help transmit high-frequency vibrations generated by particles within the slope.These vibrations pass up the tube and are picked up by a sensor on the surface.Software analyses the vibration signal to determine whether a landslide may be imminent.The device is currently being tested in a 6-metre-tall artificial clay embankment(堤岸)in Newcastle, UK.Early results suggest it should provide fewer false positives than existing systems.Once it has been carefully and thoroughly tested,the device could be used to create a complete early-warning system fordangerous slopes."Locations with a significant risk of landslides could definitely benefit from a machine like this,"says Adam Poulter,an expert at the British Red Ci?oss,"As long as it doesn't cost too much."But,Poulter adds that an early-warning system may not be enough on its own."You need to have the human communication." he says,"Making systems that get warnings to those who need them can be difficult."
[多选题]共用题干 第一篇Energy and Public LandsThe United States boasts substantial energy resources?Federal lands provide。good deal of US energy production,the US Department of the Interior manages federal energy leasing(租赁),both on land and on the offshore Outer Continental Shelf. Production from these sources amounts to nearly 30 percent of total annual US energy production.In 2000,32 percent of US oil,35 percent of natural ga9,and 37 percent Of coal were produced from federal lands,representing 20,000 producing oil and gas leases and 135 producing coal leases.Federal lands are also estimated to contain approximately 68 percent of all undiscovered US oil reserves and 74 percent of undiscovered natural gas.Revenues from federal oil,gas,and coal leasing provide significant returns to US taxpayers as well as State government,In 1999,for example,$553 million in oil and gas revenues were paid to the US Treasury,and non-Indian coal leases accounted for over $304 million in revenues, of which 50 percent were paid to State governments,Public lands also play a critical role in energy delivery.Each year,federal land managers authorize rights of way for transmission lines,rail systems,pipelines,and other facilities related to energy production and use.Alternative energy production from federal lands falls behind conventional energy production,though the amount is still significant. For example , federal geothermal (地热)resources produce about 7. 5 billion kilowatt-hours(千瓦时)of electricity per year , 47 percent of all electricity generated from US geothermal energy.There are 2,960 wind turbines on public lands in California alone,producing electricity for about 300 ,000 people. Federal hydropower(水电)facilities produce about 17 percent of all hydropower produced in the United States.Because of the growing US thirst for energy and increasing public unease with dependence on foreign oil sources,pressure on public lands to meet US energy demnand is becoming more intense.Public lands areavailable for energy development oniy after they have been evaivated through the land use planning process. If development of energy resources conflicts with management or use of other resources,development restric- lions or impact moderation measures may be enforced,or mineral production may he banned altogether. Which of the following statements is true of public lands in the U.S.?
[多选题]共用题干 Lakes,Too,Feel Global WarmingThere's no doubt;In the last few decades,the average temperature on Earth has been higher than it hasbeen in hundreds of years,Around the world,people are starting to measure the effects of global warming一 and trying to figure out what to do about it.Scientists recently used satellites to study the temperatures of lakes around the world,and they found that lakes are heating up.Between 1985 and 2009,satellites recorded the nighttime temperatures of the sur- faces of 167 lakes.During those 24 years,the lakes got warmer一by an average of about 0.045 degreeCelsius per year.In some places,lakes have been warming by as much as 0.10 degree Celsius per year. At that rate,a lake may warm by a full degree Celsius in just 10 years?That difference may seem imull一you might not even notice it in your bath.But in a lake,slightly warmer temperatures could mean more algae(水藻),and algae can make the lake poisonous(有毒的)to fish.The study shows that in some regions,lakes are warming faster than the air around them.This is impor- tant because scientists often use measurements of air temperature to study how Earth is warming.By using lake temperatures as well,scientists can get a better picture of global warming.The scientists say data on lakes give scientists a new way to measure the impact of climate change around the world.That’s going to be useful,since no country is too big or too small to ignore climate change.Scientists aren't the only ones concerned、 Everyone who lives on Earth is going to be affected by the rapid warming ofthe planet.Many world leaders believe we might be able to do something about it,especially by reducing the amount of greenhouse(温室)gases we put into the air.That’s why the United Nations started the F'ramework Convention on Climate Change,or UNFCCC. Every year the convention meets,and representatives from countries around the world gather to talk about climate change and discuss global solutions to the challenges of a warming world. UNFCCC’s annual meeting will be held in Mexico this year.
[多选题]共用题干 ADHD Linked to AIF PollutantsChildren have an increased of attention problems,seen asearly as grade school,if their no-ses inhaled(吸入)a certain type of air pollution when they were pre, ant.That,5 the finding ofa new study.Released when things aren't burned completely,this pollution 15 known as polycyclic aromatic hydrocarbons,or PAHs.Tlle higgest sources of these PAHs:the bunling of fossil fuels, wood and trash.Frederica Perera works at Columbia University,5 Mailman School of Public Health in New York City.She researclies how exposure to things in the environment affects children,5 health.In a new study,she and her team studied the exposure to air pollution of 233 nonsmokingpre,ant women in New York City.Because burning tobacco can spew(排放)PAHs into the air and lungs, Perera,5 team focused on nonsmokers.The researchers wanted to probe(探查)other sources of PA Hs,ones that,5 would have been hard for an individual to avoid.The team started by testing the blood of each woman during pregnancy.The reason:Any PA H 5 in a woman's blood would also be available to the baby in her womb.Nine years later,the researchers investigated signs of attention problems in those children,now age 9 .They asked each child’s mother a series of questions.These included whatever her child had prohlems doing things that needed sustained(长期的)mental effort,such as homework or games with friends.The sci-entists also asked if the kids had trouble following instructions or made frequent,careless mis-takes.All of these can be symptoms of a disorder called Attention Deficit Hyperactivity Disorder, or ADHD.About one in U.5.children has ADHD.Among the women studied,traffic and home heating were the primary sources of air pollution exposure,Pereraand her team suspect.Some of these women had low levels of PAHs in their blood.others had high levels.Those with high levels were five times as likely to have children who showed attention problems by age 9 .The new findings were published November 5 in the journal PLOS ONE. The main purpose of the research was to find out how exposure to PAHs played a role in har-ming the subjects' physical health.
[多选题]共用题干 The first navigational lights in the New World were probably lanterns hung at harbor en-trances .The first lighthouse was put up by the Massachusetts Bay Colony in 1716 on Little Brewster Island at the entrance to Boston Harbor. Paid for and maintained by“light dues”levied(征收)on ships,the original beacon was blown up in 1776.Until then there were only a dozen or so true lighthouses in the colonies .Little over a century later,there were 700 lighthouses.The first eight lighthouses erected on the West Coast in the l850s featured the same basic New England design:a Cape Cod dwelling with the tower rising from the center or standing close by .In New England and elsewhere,though,lighthouses reflected a variety of architectural styles.Since most stations in the Northeast were set up on rocky eminences(高处),enormous towers were not the rule .Some were made of stone and brick,others of wood or metal. Some stood onpilings or stilts;some were fastened to rock with iron rods.Farther south,from Maryland through the Florida Keys,the coast was low and sandy.It was often necessary to build tall towers there—massive structures like the majestic lighthouse in Cape Hatteras,North Carolina,which was lit in 1870.190 feet high,it is the tallest brick lighthouse in the country.Not withstanding differences in construction appearance,most lighthouses in America shared several features:a light,living quarters,and sometimes a bell(or,later,a foghorn).They also had something else in common:a keeper and usually the keeper's family.The keeper's essential task was trimming the lantern wick(灯芯)in order to maintain a steady,bright flame. The earli-est keepers came from every walk of life,they were seamen,farmers,mechanics,rough mill hands and appointments were often handed out by local customs commissioners as political plums. After the administration of lighthouse was taken over in 1852 by the United States Lighthouse Board,and agency of the Treasury Department,the keeper corps gradually became highly profes- sional. We can know from the passage that the coast of North Carolina is______.
[多选题]共用题干 Animal's"Sixth Sense"A tsunami was triggered by an earthquake in the Indian Ocean in December,2004.It killed tens of thousands of people in Asia and East Africa. Wild animals,______(51),seem to have escaped that terrible tsunami .This phenomenon adds weight to notions that they possess a"sixth sense"for______(52),experts said.Sri Lankan wildlife officials have said the giant waves that killed over 24,000 people along the Indian Ocean island's coast clearly______(53)wild beasts,with no dead animals found."No elephants are dead,not______(54)a dead mbbit. I think animals can______(55)dis-aster. They have a sixth sense.They know when things are happening,"H. D. Ratnayake,deputy director of Sri Lanka's Wildlife Department,said about one month after the tsunami attack. The______(56) washed floodwatei up to 2 miles inland at Yala National Park in the ravaged southeast,Sri Lanka's biggest wildlife______(57)and home to hundreds of wild elephants and several leopards."There has been a lot of apparent evidence about dogs barking or birds migrating______(58)volcanic eruptions or earthquakes. But it has not been proven,"said Matthew van Lierop,an animal behavior______(59)at Johannesburg Zoo."There have been no______(60)studies because you can't really test it in a lab or field setting,"he told Reuters.Other authorities concurred with this______(61)."Wildlife seem to be able to pick up certain______(62),especially birds... there are many reports of birds detecting impending disasters,"said Clive Walker,who has written several books on African wildlife.Animals certainly______(63)on the known senses such as smell or hearing to avoid dan-ger such as predators.The notion of an animal"sixth sense”-or______(64)other mythical power-is an endur-ing one which the evidence on Sri Lanka's ravaged coast is likely to add to.The Romans saw owls______(65)omens of impending disaster and many ancient cul- tures viewed elephants as sacred animals endowed with special powers or attributes. 54._________
[多选题]共用题干 Homosexuals(同性恋者)Many homosexuals prefer to be called gay or,for woman,lesbian.Most of them live quiet lives just______(51)anyone else.Some gay people have always raised children,______(52)or with partners,and the use of artificial insemination(人工受精)is increasing among lesbians.Gay persons are in every kind of job.Some are very open about their homosexuality,and some are more private.Some______(53)their sexual orientation as a biological given and others as a choice.For those women who see it as a choice,one reason often given is the inequality in most heterosexual(异性恋的)relationships.Homosexuality has been common in most cultures throughout history and generally______ (54).As a result,homosexual activity became a crime,______(55)which the penalty in early courts was death.Homosexual behavior is still______(56)in many countries and the United States.Homosexuality later came to be viewed widely as less a sin than a sickness,but now no mentalhealth professional(具有专业资格的人)any longer ______ (57) homosexuality an illness. More recent theories to______(58)for homosexuality have included those based on biological and sociological factors.To date.______(59),there is no conclusive general theory that can explain the cause of homosexuality.Attitudes______(60)homosexuality began to change in the second half of the 20th century. Gays attribute this,in part,to their own struggle for their rights and pride in their orientation. Some large companies now______(61)health-care benefits to the life partners of their gay employees. Many cities also have officially appointed lesbian and gay advisory(咨询的)committees.______(62)some attitudes have changed,however,prejudice(偏见)still exists,and in the late 1980s and early 1990s,there were considerable shouts against homosexuals,with attempt to ______(63)laws forbidding the granting of basic civil rights to gays.The AIDS epidemic,which started in the 1980s,has devastated(毁坏)the gay community and brought it together as never before,The organized gay response to the lack of government financial support for fighting AIDS and to the needs of the thousands of AIDS victim______(64)they be gays or not,has been a model of community action.AIDS,however,has also______(65)people with another reason for their prejudice. _________(65)
[多选题]共用题干 Citizen ScientistsUnderstanding how nature responds to climate change will require monitoring key life cycle events-flowering,the appearance of leaves,the first frog calls of the spring-all around the world.But ecologists can't be______(51)so they are turning to non-scientists,sometimes called citizen scientists,for help.Climate scientists are not present everywhere.______(52)there are so many places in the world and not enough scientists to observe all of them,they are asking for your help in_______(53)signs of climate change across the world.The citizen scientist movement encourages______(54)people to observe a very specific research interest-birds,trees,flowers budding,etc-and send their observations______(55)a giant database to be observed by professional scientists.This helps a small number of scientists track a______(56)amount of data that they would never be able to gather on their own.______(57)like citizen journalists helping large publications cover a hyper-local beat,citizen scientists are ready for the conditions where they live.______(58)that's needed to become one is a few minutes each day or each week to gather data and_______(59)it in.A group of scientists and educators launched an organization last year______(60) the NationalPhenology(生物气候学)Network."Phenology" is what scientists call the study of the timing of events in nature.One of the group's first efforts relies on scientists and non-scientists______(61)to collect data about plant flowering and leafing every year.The program,called Project BudBurst,collects life cycle______(62)on a variety of common plants from across the United States.People participating in the project-which is______(63)to everyone-record their observations on the Project BudBurst website."People don't______(64)to be plant experts-they just have to look around and see what's in their neighborhood,"says Jennifer Scheartz,an education consultant with the project."As we collect this data,we'11 be able to make an'estimate of______(65)plants and communities of plants and animals will respond as the climate changes." _________63
[多选题]共用题干 Lakes,Too,Feel Global WarmingThere's no doubt;In the last few decades,the average temperature on Earth has been higher than it hasbeen in hundreds of years,Around the world,people are starting to measure the effects of global warming一 and trying to figure out what to do about it.Scientists recently used satellites to study the temperatures of lakes around the world,and they found that lakes are heating up.Between 1985 and 2009,satellites recorded the nighttime temperatures of the sur- faces of 167 lakes.During those 24 years,the lakes got warmer一by an average of about 0.045 degreeCelsius per year.In some places,lakes have been warming by as much as 0.10 degree Celsius per year. At that rate,a lake may warm by a full degree Celsius in just 10 years?That difference may seem imull一you might not even notice it in your bath.But in a lake,slightly warmer temperatures could mean more algae(水藻),and algae can make the lake poisonous(有毒的)to fish.The study shows that in some regions,lakes are warming faster than the air around them.This is impor- tant because scientists often use measurements of air temperature to study how Earth is warming.By using lake temperatures as well,scientists can get a better picture of global warming.The scientists say data on lakes give scientists a new way to measure the impact of climate change around the world.That’s going to be useful,since no country is too big or too small to ignore climate change.Scientists aren't the only ones concerned、 Everyone who lives on Earth is going to be affected by the rapid warming ofthe planet.Many world leaders believe we might be able to do something about it,especially by reducing the amount of greenhouse(温室)gases we put into the air.That’s why the United Nations started the F'ramework Convention on Climate Change,or UNFCCC. Every year the convention meets,and representatives from countries around the world gather to talk about climate change and discuss global solutions to the challenges of a warming world. Scientists generally focus on air temperatures when studying global warming.
[多选题]共用题干 New Research Lights the Way to Super-fast Computers1. New research published today in the journal Nature Coniniunications,has demonstrated how glass can be manipulated to create a material that will allow computers to transfer information using light. This development could significantly increase computer processing speeds and power in the future.2. The research by the University of Surrey,in collaboration with the University of Cambridge and the University of Southampton,has found it is possible to change the electronic properties of amorphous chalcogenides,a glass material integral to data technologies such as CDs and DVDs. By using a technique called ion doping,the team of researchers have discovered a material that could use light to bring together different computing functions into one component,leading to all-optical systems.3. Computers currently use electrons to transfer information and process applications.On the other hand,data sources such as the Internet rely on optical systems:the transfer of information using light. Optical fibres are used to send information around the world at the speed of light,but these signals then have to be converted to electrical signal once they reach a computer,causing a significant slowdown in processing.4 .“The challenge is to find a single material that can effectively use and control light to carry information around a computer. Much like how the web uses light to deliver information,we want to use light to both deliver and process computer data,”said project leader,Dr. Richard Curry of the University of Surrey.5 .“This has eluded researchers for decades,but now we have shown how a widely used glass Call be manipulated to conduct negative electrons,as well as positive charges,creating what are known as‘pn-junction'devices. This should enable the material to act as a light source,a light guide and a light detecto—something that can carry and interpret optical information.In doing so,this could transform the computers of tomorrow,allowing them to effectively process infonna- tion at much faster speeds.”6. The researchers expect that the results of this research will be integrated into computers within ten years .In the short term,the glass is already being developed and used in next-generation computer memory technology known as CRAM,which may ultimately be integrated with the advances reported. Paragraph 5_________
[多选题]共用题干 Animal's"Sixth Sense"A tsunami was triggered by an earthquake in the Indian Ocean in December,2004.It killed tens of thousands of people in Asia and East Africa. Wild animals,______(51),seem to have escaped that terrible tsunami .This phenomenon adds weight to notions that they possess a"sixth sense"for______(52),experts said.Sri Lankan wildlife officials have said the giant waves that killed over 24,000 people along the Indian Ocean island's coast clearly______(53)wild beasts,with no dead animals found."No elephants are dead,not______(54)a dead mbbit. I think animals can______(55)dis-aster. They have a sixth sense.They know when things are happening,"H. D. Ratnayake,deputy director of Sri Lanka's Wildlife Department,said about one month after the tsunami attack. The______(56) washed floodwatei up to 2 miles inland at Yala National Park in the ravaged southeast,Sri Lanka's biggest wildlife______(57)and home to hundreds of wild elephants and several leopards."There has been a lot of apparent evidence about dogs barking or birds migrating______(58)volcanic eruptions or earthquakes. But it has not been proven,"said Matthew van Lierop,an animal behavior______(59)at Johannesburg Zoo."There have been no______(60)studies because you can't really test it in a lab or field setting,"he told Reuters.Other authorities concurred with this______(61)."Wildlife seem to be able to pick up certain______(62),especially birds... there are many reports of birds detecting impending disasters,"said Clive Walker,who has written several books on African wildlife.Animals certainly______(63)on the known senses such as smell or hearing to avoid dan-ger such as predators.The notion of an animal"sixth sense”-or______(64)other mythical power-is an endur-ing one which the evidence on Sri Lanka's ravaged coast is likely to add to.The Romans saw owls______(65)omens of impending disaster and many ancient cul- tures viewed elephants as sacred animals endowed with special powers or attributes. 58._________
[多选题]共用题干 Early Ideas about the Universe1 Early man got his ideas about the universe by looking at the stars as you do.He observed carefully,and learned many things about the sun,the moon,and the stars.2 Suppose you were asked to collect evidence about the sun as early man did.You might go out morning after morning and see it come up in the east.Even on cloudy mornings,youwould observe that the darkness goes away and the world becomes light.You might not see the sun but would be sure it is there,because you notice that the earth warms up.As you continued,the sun climbs higher in the sky each day during part of the year. It stays in the sky longer. The earth gets warmer. Things begin to grow. It is spring and then summer.3 After a while the sun stays in the sky for shorter and shorter periods.Many plants begin to die.Leaves fall.Winter comes.Year after year this is repeated and you cannot tell exactly why it happens.But you realize that the sun seems to make the difference. Primitive(原始的)man felt that since the sun was so powerful it must be a god. It may seem silly to us now to worship(崇拜)a sun-god, but primitive man was right about the importance of the sun to life on earth.4 You have been told that the world is round.But suppose no one had ever taught you that the world was like a huge ball.Would you have ever thought of it yourself?You cannot see the curve(曲线)of the earth at once. You would have no idea of how big it was. That's why early man believed that the earth was small and flat.Such ideas appeared from the evidence they had.5 If you watch the stars night after night,you will see them rise and set.As you look at the sky,it is not difficult to imagine that you are in the center of a vast collection of twinkling(闪烁)lights. Some early astronomers(天文学家)believed the sky was a crystal shell or series of crystal shells,one inside the other. They believed this because that is what the night sky looked like.For many centuries,men believed that the earth was the center of the universe and that the sun,the moon,and the stars circled around it. Early astronomers believed that the sky was a crystal shell or series of crystal shells because_________.
[多选题]共用题干 Verity Allen's New Show on Colors1 Different colors can affect us in many different ways;that's according to Verity Allen.In her new se- ries'Color me Healthy',Verity looks at the ways that colors can influence how hard we work and thechoices we make.They can even change our emotions and even influence how healthy we arc.2 "Have you ever noticed how people always use the same colors for the same things?" says Verity."Ourtoothpaste is always white or blue or maybe red.It'g never green.Why not?For some reason we think that blue and white is clean,while we think of green products as being a bit disgusting. It's the same for businesses.We respect a company which writes its name in blue or black,but we don't respect one that uses pink or orange.People who design new products can use these ideas to influence what we buy."3 During this four-pait series,Verity studies eight different colors,two colors in each program.Shemeets people who work in all teipects of the color industry,from people who design food packets to people who name the colors of lipsticks.4 Some of the people she meets clearly have very little scientific knowledge to support their ideas,such as the American"Color Doctor"who believes that serious diseases can be cured by,he use of colored lights. However,she also interviews real scientists who are studying the effects of green and red lights on mice,withsome surprising results.5 Overall,it's an interesting show,and anyone who watches it will probably find out something new.But because Verity goes out of her way to be polite to everyone she meets on the series,it's up to the viewers to make their own decisions about how much they should believe. People who_____________can use the ideas of colors to influence what we buy.
[多选题]共用题干 The History of the Fridge 1 The fridge is considered a necessity.It has been so since the l960s when packaged food first appeared with the label:"store in the refrigerator." 2 In my fridgeless fifties childhood,I was fed well and healthily.The milkman came daily,the grocer, the butcher,the baker,and the ice-cream man delivered two or three times a week.The Sunday meat would last until Wednesday and surplus bread and milk became all kinds of cakes.Nothing was wasted and we were never troubled by rotten food.Thirty years on,food deliveries have ceased,fresh vegetables are almost unobtainable in the country. 3 The invention of the fridge contributed comparatively little to the art of food preservation.A vast variety of well-tried techniques already existed-natural cooling,drying'smoking'salting'sugaring,bottling… 4 What refrigeration did promote was marketing-marketing hardware and electricity,marketing soft drinks,marketing dead bodies of animals around the globe in search of。good price. 5 Consequently,most of the world's fridges are to be found,not in the tropics where they might prove useful,but in the wealthy countries with mild temperatures where they are climatically almost unnecessary.Every winter,millions of fridges hum away continuously and at vast expense,busily maintaining an artificially-cooled space inside an artificially-heated house-while outside,nature provides the desired temperature free of charge. 6 The fridge's effect upon the environment has been evident,while its contribution to human happiness has been insignificant.If you don't believe me,try it yourself.Invest in。food cabinet(橱柜)and turn off your fridge next winter.You may miss the hamburgers but at least you’ll get rid of that terrible hum. Before fridges came into use,it was still possible for people to have fresh foods because______.
[多选题]共用题干 第二篇Don't Count on Dung(粪便)Conservationists(自然保护主义者)may be miscalculating the numbers of the threatened animals such as elephants,say African and American researchers. The error occurs because of a flaw in the way they estimate animal numbers from the piles of dung(粪)the creatures leave behind.The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions according to Andrew Plumptre of the Wildlife Conservation Society(WCS)in New York.Biologist Katy Payne of Cornell University in Ithaca,New York,agrees,"We really need to know elephant numbers and the evidence that we have is quite indirect,"says Payne,who electronically tracks elephants.Counting elephants from planes is impossible in the vast rainforests of Central Africa. So researchers often estimate elephant numbers by counting dung piles in a given area. They also need to know the rate at which dung decays because it's extremely difficult to determine these rates. However,researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment. "Using the wrong values can lead the census astray(离开正道),"says Plumptre.He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Cameroon.They found that the dung decayed between 55 and 65 percent more slowly than the dung in the rainforests of neighbouring Gabon.If researchers use decay rates from Gabon to count elephants in Cameroon,they would probably find more elephants than are actually around.This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally,says Plumptre"However accurate your dung density estimate might be,the decay rate can severely affect the result."Plumptre also says that the dung-pile census should be carried out over a region similar in size to an elephant's natural range.The usual technique of monitoring only small,protected areas distorts numbers because elephants move in and out of these regions,he says"If the elephant population increases within the protected area,you cannot determine whether it is a real increase or whether it is due to elephants moving in because they are being poached(入侵偷猎)outside."Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests,tracks or burrows(地洞). Piles of dung can't be relied upon when it comes to estimating elephant numbers because______.
[多选题]共用题干 Mad Scientist Stereotype Outdated Do people still imagine a physicist as a bearded man in glasses or has the image of the mad scientist changed? The Institute of Physics set out to find out whether the stereotype of a physics"boffin"(科学家) still exists by conducting a survey on shoppers in London.The people were asked to identify the physicist from a photograph of a line-up of possible suspects.98 percent of those asked got it wrong.The majority of people picked a white male of around 60,wearing glasses and with a white beard. While this stereotype may have been the image of an average physicist fifty years ago,the reality is now very different.Since 1960 the number of young women entering physics has doubled and the average age of a physicist is now 31. The stereotype of the absent-minded scientist has lasted a long time because the media and Hollywood help promote the image of men in white lab coats with glasses sitting by blackboards full of equations(等式) or working with fizzing(嘶嘶响)test tubes.These stereotypes are really damaging to society.Very good school children are put off studying science because they don't see people like themselves on television or in magazines doing science.They simply don't relate to the media's image of the mad scientist. This is one reason why fewer young people are choosing to do science at university.if we want to encourage more young people to study science subjects,we need to change this image of the scientist and make science careers more attractive.But we must also develop children's interest in science. In an attempt to change this negative image,an increasing number of science festivals are being organized. Thousands of people from secondary schools are also encouraged to take part in nationwide science competitions, of which the most popular are the National Science Olympiads.Winning national teams then get the opportunity to take part in the International Science Olympiads which are held in a different country every year.These events are all interesting for the young people who take part in but they only involve a small proportion of students who are already interested in science.It seems that there is a long way to go before science becomes attractive as subjects like computer studies or fashion and design. The.International Science Olympiads are held once every two years.
[多选题]共用题干 Animal's"Sixth Sense"A tsunami was triggered by an earthquake in the Indian Ocean in December,2004.It killed tens of thou- sands of people in Asia and East Africa. Wild animals,______________(51),seem to have escaped that terrible tsunami.This phenomenon adds weight to notions that they possess a"sixth sense"for______________(52),cx-perts said.Sri Lankan wildlife officials have said the giant waves that killed over 24,000 people along the Indian Ocean island's coast clearly______________(53)wild beasts,with no dead animals found."No elephants are dead,not______________(54)a dead rabbit.I think animals can______________(55) disaster.They have a sixth sense.They know when things are happening."H.D.Ratnayake,deputy director of Sri Lanka's Wildlife Department,said about one month after the tsunami attack.The______________(56) washed floodwaters up to 2 miles inland at Yala National Park in the ravaged southeast,Sri Lanka's biggest wildlife______________(57)and home to hundreds of wild elephants and several leopards."There has been a lot of______________(58)evidence about dogs barking or birds migrating before vol- came eruptions or earthquakes.But it has not been proven,"said Matthew van Lierop an animal behavior ______________(59)at Johannesburg Zoo."There have been no______________(60)studies because you can't really test it in a lab or field set-ting,"he told Reuters.Other authorities concurred with this______________(61)."Wildlife seem to be able to pick up certain______________(62),especially birds…there are many re-ports of birds detecting impending disasters."said Clive Walker,who has written several books on African wildlife.Animals_______________(63)rely on the known senses such as smell or hearing to avoid danger such as predators.The notion of an animal"sixth sense”-or_______________(64)other mythical power一is an enduring one which the evidence on Sri Lanka's ravaged coast is likely to add to.The Romans saw owls______________(65)omens of impending disaster and many ancient cultures viewed elephants as sacred animals endowed with special powers or attributes. _________(64)
[多选题]共用题干 Do You Have a Sense of Humor?Humor and laughter are good for us.There is increasing evidence that they can heal us physically,mentally, emotionally,and spiritually.In fact,every system of the body responds to laughter in some positive,healing way,So how can we get more laughter into our lives?______(46)Psychologist and author,Steve Wilson,has some answers。Many people believe that we are born with a sense of humor.They think,"Either you've got it,or you don't."Dr.Wilson points out that this is false.______(47)The parts of the brain and central nervous system that control laughing and smiling are mature at birth.______(48)(After all,when a baby laughs,we don't rush over and say,"That kid has a great scm of humor!")A sense of humor is something that you can develop over a lifetime.Sometimes people think that they don't have a good sense of humor because they are not good joke tellers.Dr.Wilson reminds us that telling jokes is only one of many ways to express humor.______(49) Then we will make others laugh,too.A person who has a true sense of humor is willing and able to see the funny side of everyday life.One of the best definitions of a sense of humor is"the ability to see the nonserious element in a situation".Consider this sign from a store window:"Any faulty merchandise will be cheerfully replaced with merchandise of equal quality."The store manager probably placed the sign in the window to impress customers with the store's excellent service.______(50)As Dr.Wilson says,"A good sense of humor means that you don't have to be funny;you just have to see what's funny." ______(49)
[多选题]共用题干 Cerms(细菌) on BanknotesPeople in different countries use different types of money:yuan in China,pesos in Mexico,pounds in the United Kingdom,dollars in the United States,Australia and New Zealand.They may use different cur-rencies,but these countries,and probably all countries,still have one thing in ________(51):germs on the banknotes.Scientists have been studying the germs on money for well over 100 years.At the turn of the 20th ______(52),some researchers began to suspect that germs living on money could spread disease.Most studies of germy money have looked at the germs on the currency_________(53)one country. In a new study,Frank Vriesekoop and other researchers compared the germ populations found on bills of dif-ferent ________(54)Vriesekoop is a microbiologist at the University of Ballarat in Australia.He led the study,which corn-pared the germ populations found on money _______(55)from 10 nations.The scientists studied 1,280 banknotes in total;all came from places where people buy food,like supermarkets,street vendors andcafes,________ (56)those businesses often rely on cash.Overall,the Australian dollars hosted the fewest live bacteria一no more than 10 per square centimeter. Chinese yuan had the________(57)一about 100 per square centimeter. Most of the germs on money probably would not cause harm.What we call "paper money"________(58)isn'tmade from paper. The U.S.dollar,for example,is printed on fabric that is mostly cotton.Different countries may use different________(59)to print their money. Some of the currencies studied by Vriesekoop and his team,such as the American dollar,were made from cotton.Others were made from polymers.The three_______(60)with the lowest numbers of bacteria were all printed on polymers.They included the Australian dollar,the New Zealand dollar and some Mexican pesos.The_________(61)currencies were printed on fabric made mostly of cotton.Fewer germs lived on the polymer notes.This_______(62)suggests that germs have a harder time staying alive on polymersurfaces.Scientists need to do more studies to understand _________(63)germs live on money一andwhether or not we need to be concerned.Vriesekoop is now starting a study that will______(64)the amounts of time bacteria can stay alive on different types of bills.Whatever Vriesekoop finds,the fact remains:Paper money_________(65)germs.We should wash our hands after touching it.After all,you never know where your money's been.Or what's living on it. _________(54)
[多选题]共用题干 第三篇Shouldn't We Know Who Invented the Windshield WiperWe know the famous ones一the Thomas Edison and the Alexander Graham Bells一but what about the less famous inventors?What about the people who invented the traffic light and the windshield wiper(雨刷器)?Shouldn' t we know who they are?Joan Mclean thinks so.In fact,Mclean,a professor of physics at Mountain University in Range,feels so strongly about this matter that she's developed a course on the topic.In addition to learning" who"invented"what",however,Mclean also likes her students to learn the answers to the"why"and"how" questions.According to Mclean,"when students learn the answers to these questions,they are better prepared to recognize opportunities for inventing and more motivated to give inventing a try".Her students agree.One young man with a patent for an unbreakable umbrella is walking proof of McLean's statement."If I had not heard of the story of the windshield wiper's invention,"said Tommy Lee,a senior physics major,"I never would have dreamed of turning my bad experience during a rainstorm into something so constructive."Lee is currently negotiating to sell his patent to an umbrella producer.So,just what is the story behind the windshield wiper? Well,Mary Anderson came up with the idea in 1902 after a visit to New York City. The day was cold and stormy,but Anderson still wanted to see the sights,so she jumped aboard a streetcar. Noticing that the driver was struggling to see through the snow covering the windshield,she found herself wondering why there couldn't be a built-in device for cleaning the window. Still wondering about this when she returned home to Birmingham,Alabama,Anderson started drafting out solutions. One of her ideas,a lever(操作杆)on the inside of a vehicle that would control an arm on the outside,became the first windshield wiper.Today we benefit from countless inventions and innovations,It's hard to imagine driving without Garrett A.Morgan's traffic light. It'5equally impossible to picture a world without Katherine J. Blodgett's innovation that makes glass invisible.Can you picture life without clear windows and eyeglasses? By mentioning"traffic light"and"windshield wiper",the author indicates that countless inventions are______.
[多选题]共用题干 Giant StructuresIt is an impossible task to select the most amazing wonders of the modern world since every year more ________ (51)constructions appear. Here are three giant structures which are worthy of our admiration _______(52)they may have been surpassed by some more recent wonders.The Petronas TowersThe Petronas Towers were the tallest buildings in the world when they were completed in 1999.________(53)a height of 452 metres,the tall twin towers,like two thin pencils, dominate the city of Kuala Lumpur. At the 41 st floor,the towers are_________(54)by a bridge,symboli- zing a gateway to the city.The American architect Cesar Pelli designed the skyscrapers.Constructed of high- strength concrete,the building_______(55)around 1,800 square metres of office space on every floor. And it has a shopping centre and a concert hall at the base.Other_(56)of this impressive building include double-decker lifts,and glass and steel sunshades.The Millau BridgeThe Millau Bridge was opened in 2004 in the Tarn Valley,in southern France.Atthe ________ (57)it was built,it was the world'S highest bridge,_________(58)over 340m at the highest point.The bridge is described as one of the most amazingly beautiful bridges in the world.It was built to _________ ( 59 ) Millau ' s congestion(拥堵)problems. The bridge was built to withstand the ________(60)extreme seismic(地震的)and climatic conditions. Besides,it is guaranteed for 120 years!The Itaipu DamThe Itaipu hydroelectric power plant is one of the largest constructions of its kind inthe world. It_________(61)of a series of dams across the River Parana,_________(62)forms a naturalborder between Brazil and Paraguay.Started in 1975 and taking 16 years to complete,the construction was carried out as a joint project between the two________(63).The dam is well-known for both its electricity output and its size.In 1995 it produced 78% of Paraguay’s and 25% of Brazil’s_________(64)needs.In its construction,the amount of iron and steel used was equivalent to over 300 Eiffel Towers.It is a ________(65)amazing wonder of engineering. _________(53)
[多选题]共用题干 Paper or plastic?Take a walk along the Chesapeake Bay,and you are likely to see plastic bags floating in the water. Ever since these now ubiquitous symbols of American super-consumption showed up in the supermarkets,plastic shopping bags have made their______(51)into local waterways,and from there,into the bay,where they can______(52)wildlife. Piles of them一the______(53)takes centuries to decompose一show up in landfills and on city streets.Plastic bags also take an environmental toll in the form of millions of barrels of oil expended every year to produce them.Enter Annapolis______(54)you will see plastic bags distributed free in department stores and supermarkets.Alderman Sam Shropshire has introduced a well-meaning proposal to ban retailers ______(55) distributing plastic shopping bags in Maryland's capital. Instead,retailers would be required to offer bags______(56)recycled paper and to sell reusable bags.The city of Baltimore is considering a similar measure.Opponents of the idea,however,argue that______(57)bags are harmful,too:they cost more to make,they consume more______(58)to transport,and recycling them causes more pollution than recycling plastic.The argument for depriving Annapolis residents of their plastic bags is.______(59)accepted.Everyone in this______(60)is right about one thing:disposable shopping bags of any type are______(61),and the best outcome would be for customers to reuse bags instead.Annapolis's mayor is investigating how to hand out free,reusable shopping bags to city residents,a proposal that can proceed regardless of whether other bags are banned.A less-expensive______(62)would be to encourage retailers to give discounts to customers______(63)bring their own,reusable bags,a policy that a spokesman for the supermarket Giant Food says its chain already has in place.And this policy would be more______(64)if stores imitated furniture mega-retailer Ikea and charged for disposable bags at the checkout counter. A broad ban on the use of plastic shopping bags,which would merely replace some forms of pollution with others,is not the______(65). _________(64)
[多选题]共用题干 The Need to RememberSome people say they have no memory at all:"I just can't remember a thing!"But of course we all have a memory.Our memory tells us who we are.Our memory helps us to make use in the present of what we have learnt in the past.In fact we have different types of memory.For example,our visual memory helps us recall facts and places.Some people have such a strong visual memory that they can remember exactly what they have seen,for example,pages of a book,as a complete picture.Our verbal(言语的)memory helps us remember words and figures we may have heard but not seen or written:Items of a shopping list,a chemical formula,dates,or a recipe.With our emotional(情感的)memory, we recall situations or places where we had; strong feelings,perhaps of happiness or unhappiness. We also have special memories for smell,taste, touch and sound,and for performing physical movements.We have two ways of storing any of these memories. Our short-term memory stores items for up to thirty seconds-enough to remember a telephone number while we dial.Our long-term mem-ory,on the other hand,may store items for a lifetime. Older people in fact have a much biter long-term memory than short-term .They may forget what they have done only a few hours ago,but have the clearest remembrance(记忆)of when they were very young.Psychologists tell us that we only remember a few facts about our past,and that we invent the rest. It is as though we remember only the outline of a story.We then make up the details. We of-ten do this in the way we want to remember them,usually so that we appear as the heroes of our own past , or maybe victims needing sympathy(同情). Generally we remember only a few facts about the past.
[多选题]共用题干 第一篇Approaches to Understanding IntelligencesIt pays to be smart,but we are not all smart in the same way.You may be a talented musician,but you might not be a good reader.Each of us is different.Psychologists disagree about what is intelligence and what are talents or personal abilities.Psychologists have two different views on intelligence.Some believe there is one general intelligence.Others believe there are many different intelligences.Some psychologists say there is one type of intelligence that can be measured with IQ tests.These psychologists support their view with research that concludes that people who do well on one kind of test for mental ability do well on other tests.They do well on tests using words,numbers,or pictures.They do well on individual or group tests,and written or oral tests.Those who do poorly on one test,do the same on all tests.Studies of the brain show that there is a biological basis for general intelligence.The brains of intelligent people use less energy during problem solving.The brain waves of people with higher intelligence show a quicker reaction.Some researchers conclude that differences in intelligence result from differences in the speed and effectiveness of information processing by the brain.Howard Gardner,a psychologist at the Harvard School of Education,has four children.He believes thai all children are different and shouldn't be tested by one intelligence test.Although Gardner believes general intelligence exists,he doesn't think it tells much about the talents of a person outside of formal schooling.He thinks that the human mind has different intelligences.These intelligences allow us to solve the kinds of problems we are presented with in life.Each of us has different abilities within these intelligences.Gardner believes that the purpose of school should be to encourage development of all of our intelligences.Gardner says that his theory is based on biology.For example,when one part of the brain is injured,other parts of the brain still work.People who cannot talk because of brain damage can still sing.So,there is not just one intelligence to lose.Gardner has identified 8 different kinds of intelligence:linguistic,mathematical,spatial,musical, interpersonal, intrapersonal, body-kinesthetic(身体动觉的),and naturalistic. Gardner believes that______.
[多选题]共用题干 Look After Your VoiceOften speakers at a meeting experience dry mouths and ask for a glass of water. You can solve the problem by activating the saliva in your mouth.First gently bite the edges of your tongue with your teeth .Or,press your entire tongue to the bottom of your mouth and hold it there until the saliva flows.Or you can imagine that you are slicing a big juicy lemon and sucking the juice.Before you begin your talk,be kind'to your voice.Avoid milk or creamy drinks which dry your throat. Keep your throat wet by drinking a little sweetened warm tea or diluted fruit juice.If you sense that you are losing your voice,stop talking completely.In the meantime,do not even talk in a low voice.Save your voice for your health.You may feel foolish using paper to write notes,but the best thing you can do is to rest your voice.If it is necessary,perhaps you can get some advice from a professional singer.What about drinking alcohol to wet your throat?I advice you not to touch alcohol before speaking. The problem with alcohol is that one drink gives you a little confidence.The second drink gives you even more confidence.Finally you will feel all-powerful and you will feel you can do everything,but in fact your brain and your mouth do not work together properly.Save the alco- hol until after you finish speaking.Perhaps you want to accept the advice,but you may wonder if you can ever change the habits of a lifetime .Of course you can .Goethe,who lived before indoor skating rinks or swimming pools,said,“We learn to skate in the summer and swim in the winter”.Take this message to heart and give yourself time to develop your new habits.If you are willing to change,you will soon be able to say that you will never forget these techniques because they became a part of your body. The first paragraph mentions three ways of activating the saliva in the mouth.
[多选题]共用题干 Easy LearningStudents should be jealous.Not only do babies get to doze their days away,but they've also mastered the fine art of learning in their sleep.By the time babies are a year old they can recognize a lot of sounds and even simple words. Marie Cheour at the University of Turku in Finland suspected that they might progress this fast because they learn language while they sleep as well as when they are awake.To test the theory,Cheour and her colleagues studied 45 newborn babies in the first days of their lives. They exposed all the infants to an hour of Finnish vowel sounds一one that sounds like "oo",another like"ee"and a third boundary vowel peculiar to Finnish and similar languages that sounds like something in between. EEG recordings of the infants brains before and after the session showed that the newborns could not distinguish the sounds.Fifteen of the babies then went back with their mothers,while the rest were split into two sleepstudy groups.One group was exposed throughout their night-time sleeping hours to the same three vowels,while the others listened to the other,easier-to-distinguish vowel sounds.When tested in the morning,and again in the evening,the babies who'd heard the tricky boundary vowels all night showed brainwave activity indicating that they could now recognize this sound.They could identify the sound even when its pitch was changed,while none of the other babies could pick up the boundary vowel at all.Cheour doesn't know how babies accomplish this night-time learning,but she suspects that the special ability might indicate that unlike adults,babies don't"turn off" their cerebral cortex while they sleep.The skill probably fades in the course of the first years of life,she adds,so forget the idea that you can pick up the tricky French vowels as an adult just by slipping a language tape under your pillow. But while it may not help grown-ups,Cheour is hoping to use the sleeping hours to give remedial help to babies who are genetically at risk of language disorders. If an adult wants to learn a language faster,he can put a language tape under his pillow.
[多选题]共用题干 Renewable Energy SourcesToday petroleum(石油)provides around 40% of the world's energy needs, mostly fuelling automobiles .Coal is still used,mostly in power stations,to cover one-quarter of our energy needs, but it is the least efficient, unhealthiest and most environmentally damaging fossil fuel(矿物燃料).Natural gas reserves could fill some of the gap from oil,but reserves of that will not last into the 22nd century either. Most experts predict we will exhaust easily accessible reserves within 50 years. Less-polluting renewable energy sources offer a more practical long-term energy solution. "Renewable"refers to the fact that these resources are not used faster than they can be replaced.Hydroelectric(水力发电的)power is now the most common form of renewable energy , supplying around 20% of world electricity.China's Three Gorges Dam is the largest ever. At five times the size of the U. S. 's Hoover Dam,its 26 turbines (涡轮机)will generate the equivalent energy of 18 coal-fired power stations. It will satisfy 3%of China's entire electricity demand.In 2003,the first commercial power station to use tidal(潮汐的)currents in the open sea opened in Norway. It is designed like windmill(风车),but others take the form of turbines.As prices fall,wind power has become the fastest growing type of electricity generation-quadrupling(翻两番)worldwide between 1 999 and 2005 . Modern wind farms consist of turbines that generate electricity. Though it will be more expensive,there is more than enough wind to provide the world's entire energy needs.Wind farms come in onshore and offshore forms. They can often end up at spots of natural beauty,and are often unpopular with residents. And turbines are not totally harmless-they can interfere with radar,alter climate and kill sea birds.Scotland is building Europe's largest wind farm,which will power 200 ,000 homes. The U.K. 's goal is to generate one-fifth of power from renewable sources,mainly wind,by 2020 .But this may cause problems, because wind is unreliable.
[多选题]共用题干 So Many"Earths"The Milky Way(银河)contains billions of Earth-sized planets that could support life.That's the finding of a new study.It draws on data that came from NASA's top planet-hunting telescope.A mechanical failure recently put that Kepler space telescope out of service.Kepler had played a big role in creating a census of planets orbiting some 170,000 stars.Its data have been helping astronomers predict how common planets are in our galaxy.The telescope focused on hunting planets that might have conditions similar to those on Earth.The authors of a study,published in The Proceedings of the National Academy of Sciences,conclude that between 14 and 30 out of every 100 stars,with a mass and temperature similar to the Sun,may host a planet that could support life as we know it.Such a planet would have a diameter at least as large as Earth's,but no more than twice that big.The planet also would have to orbit in a star's habitable zone.That's where the surface temperature would allow any water to exist as a liquid.The new estimate of how many planets might fit these conditions comes from studying more than 42,000 stars and identifying suitable worlds orbiting them.The scientists used those numbers to extrapolate(推算) to the rest of the stars that the telescope could not see.The estimate is rough,the authors admit.If applied to the solar system,it would define as habitable a zone starting as close to the Sun as Venus and running to as far away as Mars.Neither planet is Earthlike (although either might have been in the distant past).Using tighter limits,the researchers estimate that between 4 and 8 out of every 100 sunlike stars could host an Earth-sized world.These are ones that would take 200 to 400 days to complete a yearly orbit.Four out of every 100 sunlike stars doesn't sound like a big number.It would mean,however,that the Milky Way could host more than a billion Earth-sized planets with a chance for life. The new finding is based on a thorough study of 170,000 stars in the Milky Way.
[多选题]共用题干 第一篇A Sunshade(遮阳伞)for the PlanetEven with the best will in the world,reducing our carbon emissions is not going to prevent global warming. It has become clear that even if we take the most strong measures to control emissions, the uncertainties in our climate models still leave open the possibility of extreme warming and rises in sea level. At the same time,resistance by governments and special interest groups makes it quite possible that the actions suggested by climate scientists might not be implemented soon enough.Fortunately,if the worst comes to the worst,scientists still have a few tricks up their sleeves. For the most part they have strongly resisted discussing these options for fear of inviting a sense of complacency that might thwart efforts to tackle the root of the problem. Until now,that is a growing number of researchers are taking a fresh look at large-scale"geoengineering"projects that might be used to counteract global warming."I use the analogy of methadone,"says Stephen Schneider,a climate researcher at Stanford University in California who was among the first to draw attention to global warming."If you have a heroin addict,the correct treatment is hospitalization,and a long rehab. But if they absolutely refuse,methadone is better than heroin."Basically the idea is to apply"sunscreen"to the whole planet. One astronomer has come up with a radical plan to cool Earth:launch trillions of feather-light discs into space,where they would form a vast cloud that would block the sun's rays.It's controversial,but recent studies suggest there are ways to deflect just enough of the sunlight reaching the Earth's surface to counteract the warming produced by the greenhouse effect. Global climate models show that blocking just 1.8 percent of the incident energy in the sun's rays would cancel out the warming effects produced by a doubling of greenhouse gases in the atmosphere.That could be crucial,because even the most severe emissions control measures being proposed would leave us with a doubling of carbon dioxide by the end of this century,and that would last for at least a century more. What does Stephen Schneider say about a heroin addict and methadone?
[多选题]共用题干 More Than 8 Hours Sleep Too Much of a Good ThingAlthough the dangers of too little sleep are widely known,new research suggests that people who sleep too much may also suffer the consequences.Investigators at the University of California in San Diego found that people who clock up 9 or 10 hours each weeknight appear to have more trouble falling and staying asleep,as well as a number of other sleep problems,than people who sleep 8 hours a night. People who slept only 7 hours each night also said they had more trouble falling asleep and feeling refreshed after a night's sleep than 8-hour sleepers.These findings,which DL Daniel Kripke reported in the journal Psychosomatic Medicine, demonstrate that people who want to get a good night's rest may not need to set aside more than 8 hours a night. He added that it might be a good idea for people who sleep more than 8 hours each night to consider reducing the amount of time they spend in bed,but cautioned that more research is needed to confirm this.Previous studies have shown the potential dangers of chronic shortages of sleep,for instance, one report demonstrated that people who habitually sleep less than 7 hours each night have a higher risk of dying within a fixed period than people who sleep more.For the current report,Kripke reviewed the responses of 1,004 adults to sleep questionnaires,in which participants indicated how much they slept during the week and whether they experienced any sleep problems.Sleep problems included waking in the middle of the night,arising early in the morning and being unable to fall back to sleep,and having fatigue interfere with day-to-day functioning.Kripke found that people who slept between 9 and 10 hours each night were more likely to report experiencing each sleep problem than people who slept 8 hours.In an interview,Kripke noted that long sleepers may struggle to get rest at night simply because they spend too much time in bed. As evidence,he added that one way to help insomnia is to spend less time in bed."It stands to reason that if a person spends too long a time in bed,then they'll spend a higher percentage of time awake,"he said. One survey showed that people who habitually______each night have a higher risk of dying.
[多选题]共用题干 Ecosystem1 The word " ecosystem" is short for ecological(生态的)system. An ecosystem is where living crea- tures expand within a given area.You can say that an ecosystem is the natural environment where biologicalorganisms(生物)such as plants,animals and humans co-exist in this world. So naturally that includes you and mne.Yes,we are all members of an ecosystem!2 There are different kinds of ecosystems depending on the type of suiface or environment. Most are naturally made 5uch as the ocean or lake and the desert or rainforest.Some are man-made or artificial to en- courage co-habitation(共居)between living and non-living things in a monitored environment,such as azoo or garden.3 Plants make up the biggest group of biological creatures within an ecosystem,and that's because they are the natural food producers for everyone.Plants raised in the earth need air and collect sunlight to help them grow.When they grow,the plants and their加its or flowers eventually become a source of food to animals,microorganisms (微生物)and even humans, of course. Food is then converted to energy for the rest of us to function,and this happens in a never-ending cycle until the living creatures die and break up back in the earth.4 Ecosystems are the basis of survival for all living things.We depend on plants and animals for food. In order for us to exist,we need to grow and care about other organisms.We also need tO care for the non一living things within our environment like our air and water so we can continue living as a population.Since plants, animals and humans are all of various species(物种),we all play a role in maintaining the ecosystem.5 To preserve our ecosystems,we should stop using too much energy,which happens汕en we consume more than our share of resources. Humans should not disturb the natural habitat(栖息地)of plants and animals, and should allow them to grow healthily for the cycle to continue.Too many people in a habitat can mean dis- placement(搬迁):imagine being thrown out of your home because there is no more space for everyone. Worse,overpopulation can also ruin the environment and cause destruction of existing plants and animals. To protect our ecosystems we should not use more than_________.
[多选题]共用题干 Squishy Cellphones Add a Buzz to CallsVibrating rubber could be the next big thing in mobile communications.They allow people to communicate by squishing the phone to transmit_______(51)along with their spoken words. According to a research team at the MIT Medical Lab in Cambridge,Massachusetts,the idea will make_______(52)more fun.Many mobile phones can already be made to vibrate(振动)_______(53 ) ring when you do not want people to know you are getting a call. But these vibrations,_______(54)by a motor spinning an eccentric(离心的、偏离的)weight inside the device, are too crude for subtle com-munication,says Angela Chang of the lab's Tangible Media Group.“They're_______(55)on or off,”she says.But when you grip Chang's prototype(样机)latex(橡胶)celiphone,your fingers and thumb wrap around five_______(56)speakers. They vibrate_______(57)your skin around 250 times per second.Beneath these speakers sit pressure sensors,so you can transmit vibration as well as_______(58)it. When you squeeze with a finger,a vibration signal is transmitted _______(59)your caller's corresponding finger. Its_______(60)depends on how hard you squeeze.She says that within a few minutes of being given_______(61)the phones,students were using the vibration feature to add emphasis to what they were saying or to interrupt the other speaker. Over time, people even began to transmit their_______ (62) kind of ad hoc(特别的)“Morse code”,which they would repeat back to show they were following what the other person was saying.“It was pretty easy to communicate,though we didn't specifically pre-arrange _______(63),”says David Milovich,one of the students who tried out the device.Chang thinks“vibralanguages”could_______(64)for the same reason as texting:some-times people want to communicate something_______(65)everyone nearby knowing what they are saying.“And imagine actually being able to shake someone's hand when you close a business seal,”she says. 52._________
[多选题]共用题干 Rescue PlatformIn the aftermath of the terrorist attacks on the World Trade Center,security experts are trying to develop new ways of rescuing people from burning skyscrapers.One________(51)is a plat-form capable of flying vertically and hovering in the air_________(52)a helicopter. The plafform would rise up and down alongside a skyscraper and pick up people_________(53)in high stories。The idea for the vertical takeoff platform was hatched(策划)more than ten years ago by a Russian aerospace engineer,David Metreveli,who has since moved to Israel. Metreveli's design, _________(54)the Eagle,calls for two jet engines that_________(55)four large horizontal pro-pellers. The spinning of the propellers_________(56)the necessary lift,or upward force,to raise the platform. The more_________(57)is supplied to the propellers,the higher the platform _________(58).Moving the platform sideways involves_________(59)differing amounts of power to each propeller.Helicopters are now used in some________(60)to get people out of burning buildings.Es-cape baskets slung from them dangle beside the building for people to climb into._________(61),the baskets cannot reach every floor of a building_________(62)the ropes from which they hang become unstable_________(63)a certain length.So far,Metreveli has built a small-scale model of the Eagle to_________(64)his idea. In the wake of September 11,he has been able to secure enough funding to start building a larger ,4- meter by 4-meter prototype,_________(65)he calls the Eaglet. 61._________
[多选题]共用题干 Giant StructuresIt is an impossible task to select the most amazing wonders of the modern world since every year more ________ (51)constructions appear. Here are three giant structures which are worthy of our admiration _______(52)they may have been surpassed by some more recent wonders.The Petronas TowersThe Petronas Towers were the tallest buildings in the world when they were completed in 1999.________(53)a height of 452 metres,the tall twin towers,like two thin pencils, dominate the city of Kuala Lumpur. At the 41 st floor,the towers are_________(54)by a bridge,symboli- zing a gateway to the city.The American architect Cesar Pelli designed the skyscrapers.Constructed of high- strength concrete,the building_______(55)around 1,800 square metres of office space on every floor. And it has a shopping centre and a concert hall at the base.Other_(56)of this impressive building include double-decker lifts,and glass and steel sunshades.The Millau BridgeThe Millau Bridge was opened in 2004 in the Tarn Valley,in southern France.Atthe ________ (57)it was built,it was the world'S highest bridge,_________(58)over 340m at the highest point.The bridge is described as one of the most amazingly beautiful bridges in the world.It was built to _________ ( 59 ) Millau ' s congestion(拥堵)problems. The bridge was built to withstand the ________(60)extreme seismic(地震的)and climatic conditions. Besides,it is guaranteed for 120 years!The Itaipu DamThe Itaipu hydroelectric power plant is one of the largest constructions of its kind inthe world. It_________(61)of a series of dams across the River Parana,_________(62)forms a naturalborder between Brazil and Paraguay.Started in 1975 and taking 16 years to complete,the construction was carried out as a joint project between the two________(63).The dam is well-known for both its electricity output and its size.In 1995 it produced 78% of Paraguay’s and 25% of Brazil’s_________(64)needs.In its construction,the amount of iron and steel used was equivalent to over 300 Eiffel Towers.It is a ________(65)amazing wonder of engineering. _________(57)
[多选题]共用题干 第二篇The Book of LifeSo far, scientists have named about 1.8 million living species(物种),and that's just a small part of what probably exists on Earth.With so many plants,animals,and other creatures covering the planet,it can be tough to figure out what type of spider is moving up your leg or what kind of bird is flying by.A soon-to-be-launched Web site mighit help. An international team of researchers has announced the creation of a Web-based Encyclopedia(百科全书)of Life(EoL).The project aims to catalog every species on Earth in a single,easy-to-use referenice guide.To get the encyclopedia started,the creators will use information from scientific databases(数据库)that already exist. And eventually , in special sections of the site , nonscientists with specialized(专门的) knowledge will get to join in Bird-watchers,for example,will be able to input which birds they'ye seen and where.The technology for this kind of tool has only recently become available.As the EoL develops,you might find it useful for school projects.The site will feature special pages for kids who are studying ecosystems(生态系统)in their neighborhoods. To make sure the encyclopedia is accurate,scientists will review much of the information added to it.People who visit the site will be able tochoose to leave out pages that haven't been reviewed.Another convenient feature of the EoL is that you'11 be able to pick the level of detail you see to match your interests,age,and current knowledge.If you wanted to learn about bears for a science class report,for example,you could use the"novice"setting to get basic information about the animals.On the"expert" setting,on the other hand,you could get much more detailed information about the history,literature,andexploration of bears.It now takes years for scientists to collect all the data they need to describe and analyze species.The creators of the Encyclopedia of Life hope that their new tool will speed that process. Which of the following statements is NOT true?
[多选题]共用题干 Late-Night DrinkingCoffee lovers beware.Having a quick"pick-me-up"cup of coffee late in the day will play havoc with your sleep .As well as being a stimulant,caffeine interrupts the flow of melatonin,the brain hormone that sends people into a sleep.Melatonin levels normally start to rise about two hours before bedtime. Levels then peak be-tween 2 am and 4 am,before falling again."It's the neurohormone that controls our sleep tells our body when to sleep and when to wake,"says Maurice Ohayon of the Stanford Sleep Epidemiology Research Center at Stanford University in California.But researchers in Israel have found that caf feinated coffee halves the body's levels of this sleep hormone.Lotan Shilo and a team at the Sapir Medical Center in Tel Aviv University found that six vol-unteers slept less well after a cup of caffeinated coffee than after drinking the same amount of de-caf. On average,subjects slept 336 minutes per night after drinking caffeinated coffee,compared with 415 minutes after decaf. They also took half an hour to drop offtwice as long as usual-and jigged around in bed twice as much.In the second phase of the experiment,the researchers woke the volunteers every three hours and asked them to give a urine sample.Shilo measured concentrations of a breakdown product of melatonin .The results suggest that melatonin concentrations in caffeine drinkers were half those in decaf drinkers .In a paper accepted for publication in Sleep Medicine,the researchers suggest that caffeine blocks production of the enzyme that drives melatonin production.Because it can take many hours to eliminate caffeine from the body,Ohayon recommends that coffee lovers switch to decaf after lunch. What does paragraph 3 mainly talk about?
[多选题]共用题干 The History of the Fridge 1 The fridge is considered a necessity.It has been so since the l960s when packaged food first appeared with the label:"store in the refrigerator." 2 In my fridgeless fifties childhood,I was fed well and healthily.The milkman came daily,the grocer, the butcher,the baker,and the ice-cream man delivered two or three times a week.The Sunday meat would last until Wednesday and surplus bread and milk became all kinds of cakes.Nothing was wasted and we were never troubled by rotten food.Thirty years on,food deliveries have ceased,fresh vegetables are almost unobtainable in the country. 3 The invention of the fridge contributed comparatively little to the art of food preservation.A vast variety of well-tried techniques already existed-natural cooling,drying'smoking'salting'sugaring,bottling… 4 What refrigeration did promote was marketing-marketing hardware and electricity,marketing soft drinks,marketing dead bodies of animals around the globe in search of。good price. 5 Consequently,most of the world's fridges are to be found,not in the tropics where they might prove useful,but in the wealthy countries with mild temperatures where they are climatically almost unnecessary.Every winter,millions of fridges hum away continuously and at vast expense,busily maintaining an artificially-cooled space inside an artificially-heated house-while outside,nature provides the desired temperature free of charge. 6 The fridge's effect upon the environment has been evident,while its contribution to human happiness has been insignificant.If you don't believe me,try it yourself.Invest in。food cabinet(橱柜)and turn off your fridge next winter.You may miss the hamburgers but at least you’ll get rid of that terrible hum. Paragraph 4______
[多选题]共用题干 Eastern Quakes can Trigger Big ShakesIn the first week of November 2011,people in central Oklahoma experienced more than two dozen earthquakes.The largest,a magnitude 5.6 quake,shook thousands of fans in a college football itadium, caused cracks in a few buildings and rattled the nerves of many people who had never felt a quake before. Oklahoma is not an area of the country famous for its quakes.If you watch the news on TV,you will see reports about all sorts of natural disasters一hurricanes,tornadoes,flooding and wildfires,to name a few.But the most dangerous type of natural disaster,and also the most unpredictable,is the earthquake.Researchers at the U.S.Geological Survey estimate that several million earthquakes rattle the globe eachyear. That mnay sound scary,but people don'I feel many of the tremors because they happen in remote and unpopulated regions.Many quakes happen under the ocean,and othlers have a very small magnitude,or shaking intensity..A magnitude 5.8 earthquake that struck central Virginia the afternoon of August 23,2011,was felt from central Georgia to southeastern Canada.In iilany urbanl areas,including Washington,D.C.,dnd New York City(Wall Street shown),people crowded the streets while engineer inspected buildings.Credit: Wikimnedia/Alex Tahak.Scientists know about small,remote quakes only because of very sensitive electronic devices called seis- mometers.These devices detect and measure the size of ground vibrations produced by earthquakes. Altogether,USGS researchers use seismornetero to identify and locate about 20,000 earthquakseach year.Although earthquakes can happen anywhere in the world,really big quakeg occur only in。erttiin areas.The largest ones register a magnitude S or higher and happen, on average,only once each year. Such big ones typically occur along the edges of Earth’s tectonic plates.Tectonic plates are huge pieces of Earth’s crust,sornetinies many kilometers thick.These plates cover our planet'ssurface ike a jigsaw puzzle.Often,jagged edges of these plates temporarily lock together. When riates jostle and serape past each other earthquakes occur. On。、crage,tectonic plates move very slowly一 about the same speed as sour fingernails grow.But sometimes earthquakes rumble through portions of the landscape far from a plate'S edges.Although less cxpcctcd,these"mid-plate"tremors can do substontaI damage,Some of the biggest known examples rattled the eastern haif of the United States two centuries ago.Today,scientists are still puzzling over why the quakes occurred and when similar ones nught occur. The earthquake is the most unpredictable natural disaster.
[多选题]共用题干 Animal's"Sixth Sense"A tsunami was triggered by an earthquake in the Indian Ocean in December,2004.It killed tens of thousands of people in Asia and East Africa. Wild animals,______(51),seem to have escaped that terrible tsunami .This phenomenon adds weight to notions that they possess a"sixth sense"for______(52),experts said.Sri Lankan wildlife officials have said the giant waves that killed over 24,000 people along the Indian Ocean island's coast clearly______(53)wild beasts,with no dead animals found."No elephants are dead,not______(54)a dead mbbit. I think animals can______(55)dis-aster. They have a sixth sense.They know when things are happening,"H. D. Ratnayake,deputy director of Sri Lanka's Wildlife Department,said about one month after the tsunami attack. The______(56) washed floodwatei up to 2 miles inland at Yala National Park in the ravaged southeast,Sri Lanka's biggest wildlife______(57)and home to hundreds of wild elephants and several leopards."There has been a lot of apparent evidence about dogs barking or birds migrating______(58)volcanic eruptions or earthquakes. But it has not been proven,"said Matthew van Lierop,an animal behavior______(59)at Johannesburg Zoo."There have been no______(60)studies because you can't really test it in a lab or field setting,"he told Reuters.Other authorities concurred with this______(61)."Wildlife seem to be able to pick up certain______(62),especially birds... there are many reports of birds detecting impending disasters,"said Clive Walker,who has written several books on African wildlife.Animals certainly______(63)on the known senses such as smell or hearing to avoid dan-ger such as predators.The notion of an animal"sixth sense”-or______(64)other mythical power-is an endur-ing one which the evidence on Sri Lanka's ravaged coast is likely to add to.The Romans saw owls______(65)omens of impending disaster and many ancient cul- tures viewed elephants as sacred animals endowed with special powers or attributes. 57._________
[多选题]共用题干 第三篇The Best Way to Reduce Your WeightYou hear this:"No wonder you are fat. All you ever do is eat."You feel sad:"I skip my breakfast and supper. I run every morning and evening. What else can I do?"Basically you can do nothing. Your genes,not your life habits,determine your weight and your body constantly tries to maintain it.Albert Stunkard of the University of Pennsylvania found from experiments that,"80 percent of the children of two obese parents become obese,as compared with no more than 14 percent of the offspring of two parents of normal weight."How can obese people become normal or even thin through dieting?Well,dieting can be effective,but the health costs are tremendous.Jules Hirsch,a research physician at Rockefeller University,did a study of eight fat people.They were given a liquid formula providing 600 calories a day.After more than 10 weeks,the subjects lost 45kg on average.But after leaving the hospital,they all regained weight. The results were surprising:by metabolic measurement,fat people who lost large amounts of weight seemed like they were starving. They had psychiatric problems.They dreamed of food or breaking their diet.They were anxious and depressed;some were suicidal. They hid food in their rooms.Researchers warn that it is possible that weight reduction doesn't result in normal weight,but in an abnormal state resembling that of starved non-obese people.Thin people,however,suffer from the opposite:They have to make a great effort to gain weight. Ethan Sims,of the University of Vermont,got prisoners to volunteer to gain weight. In four to six months,they ate as much as they could.They succeeded in increasing their weight by 20 to 25 percent. But months after the study ended,they were back to normal weight and stayed there.This did not mean that people are completely without hope in controlling their weight. It means that those who tend to be fat will have to constantly battle their genetic inheritance if they want to significantly lower their weight.The findings also provide evidence for something scientists thought was true一each person has a comfortable weight range. The range might be as much as 9kg. Someone might weigh 60-69kg without too much effort.But going above or below the natural weight range is difficult. The body resists by feeling hungry or full and changing the metabolism to push the weight back to the range it seeks. What did Ethan Sims make his subjects do?
[多选题]共用题干 A Record-Breaking RoverNASA's Mars rover Opportunity has boldly gone where no rover has gone before—at least in terms of distance. Since arriving on the Red Planet in 2004,Opportunity has traveled 25 .01 miles,more than any other wheeled vehicle has on another world.“This is so remarkable considering Opportunity was intended to drive about 1 kilometer and was never designed for distance,”says John Callas,the Mars Exploration Rover Project Manager.He works at NASA's Jet Propulsion Laboratory in Pasadena,California.“But what is really importantly is not how many miles the rover has racked up,but how much exploration and discovery we have accomplished over that distance.”The solar-powered Opportunity and its twin rover,Spirit,landed on Mars 10 years ago on a mission expected to last 3 months. The objective of the rovers was to help scientists learn more about the planet and to search for signs of life,such as the possible presence of water.Spirit stopped communicating with Earth in March 2010,a few months after it got stuck in a sand pit. But Opportunity has continued to collect and analyze Martian soil and rocks.During its mission,Opportunity has captured,and sent back to Earth,some 187,000 panoramic and microscopic images of Mars with its cameras. It has also provided scientists with data on the planet's atmosphere,soil,rocks,aid terrain.The rover doesn't seem to be ready to stop just yet. If Opportunity can continue on,it will reach another major investigation site when its odometer hits 26.2 miles. Opportunity has beer working on Mars since January 2004.Researchers believe that clay minerals exposed near Marathon Valley could hold clues to Mars's ancient environment. Opportunity's continuing travels will also help researchers as the, plan for an eventual human mission to the Red Planet. One of the objectives of sending Opportunity and Spirit is to_________.
[多选题]共用题干 More Than 8 Hours Sleep Too Much of a Good ThingAlthough the dangers of too little sleep are widely known,new research suggests that people who sleep too much may also suffer the consequences.Investigators at the University of California in San Diego found that people who clock up 9 or 10 hours each weeknight appear to have more trouble falling and staying asleep,as well as a number of other sleep problems,than people who sleep 8 hours a night. People who slept only 7 hours each night also said they had more trouble falling asleep and feeling refreshed after a night's sleep than 8-hour sleepers.These findings,which DL Daniel Kripke reported in the journal Psychosomatic Medicine, demonstrate that people who want to get a good night's rest may not need to set aside more than 8 hours a night. He added that it might be a good idea for people who sleep more than 8 hours each night to consider reducing the amount of time they spend in bed,but cautioned that more research is needed to confirm this.Previous studies have shown the potential dangers of chronic shortages of sleep,for instance, one report demonstrated that people who habitually sleep less than 7 hours each night have a higher risk of dying within a fixed period than people who sleep more.For the current report,Kripke reviewed the responses of 1,004 adults to sleep questionnaires,in which participants indicated how much they slept during the week and whether they experienced any sleep problems.Sleep problems included waking in the middle of the night,arising early in the morning and being unable to fall back to sleep,and having fatigue interfere with day-to-day functioning.Kripke found that people who slept between 9 and 10 hours each night were more likely to report experiencing each sleep problem than people who slept 8 hours.In an interview,Kripke noted that long sleepers may struggle to get rest at night simply because they spend too much time in bed. As evidence,he added that one way to help insomnia is to spend less time in bed."It stands to reason that if a person spends too long a time in bed,then they'll spend a higher percentage of time awake,"he said. Paragraph 5______
[多选题]共用题干 An Intelligent CarDriving needs sharp eyes, keen ears, quick brain, and coordination(协调)between hands and the brain.Many human drivers have all_________(1)and can control a fast-moving car. But how does an intelligent car control itself?There is a virtual(虚拟的)driver in the smart car. This virtual driver has "eyes", "brains","hands"and"feet",too.The minicameras_________(2)each side of the car are his"eyes",which_________(3)the road conditions ahead of it.They watchthe_________(4)to the car's left and right.There is also a highly automatic driving _________(5)in the car. It is the built-in computer,which is the virtual driver's "brain".His"brain"_________(6)the speeds of other moving cars near it andanalyzes their positions.Basing on this information,it chooses the_________(7)path for the intelligent car,and gives instructions to the"hands"and"feet"to act accordingly. In this way,the virtual driver_________(8)his car.What is the virtual driver's best advantage?He reacts_________(9).The minicameras are bringing_________(10)continuously to the"brain".It completes the processing of the images within 100 milliseconds._________(11),the world's best driver needs at least one second to react.Besides,when he takes_________(12),he needs one more second.The virtual driver is really wonderful.He can reduce the accident_________(13) considerably on expressways(高速公路).In this_________(14),can we let him have the wheel at any time and in any place?Experts_________(15)that we cannot do that just yet.His ability to recognize things is still limited.He can now only drive an intelligent car on expressways. _________(7)
[多选题]共用题干 Paper or plastic?Take a walk along the Chesapeake Bay,and you are likely to see plastic bags floating in the water. Ever since these now ubiquitous symbols of American super-consumption showed up in the supermarkets,plastic shopping bags have made their______(51)into local waterways,and from there,into the bay,where they can______(52)wildlife. Piles of them一the______(53)takes centuries to decompose一show up in landfills and on city streets.Plastic bags also take an environmental toll in the form of millions of barrels of oil expended every year to produce them.Enter Annapolis______(54)you will see plastic bags distributed free in department stores and supermarkets.Alderman Sam Shropshire has introduced a well-meaning proposal to ban retailers ______(55) distributing plastic shopping bags in Maryland's capital. Instead,retailers would be required to offer bags______(56)recycled paper and to sell reusable bags.The city of Baltimore is considering a similar measure.Opponents of the idea,however,argue that______(57)bags are harmful,too:they cost more to make,they consume more______(58)to transport,and recycling them causes more pollution than recycling plastic.The argument for depriving Annapolis residents of their plastic bags is.______(59)accepted.Everyone in this______(60)is right about one thing:disposable shopping bags of any type are______(61),and the best outcome would be for customers to reuse bags instead.Annapolis's mayor is investigating how to hand out free,reusable shopping bags to city residents,a proposal that can proceed regardless of whether other bags are banned.A less-expensive______(62)would be to encourage retailers to give discounts to customers______(63)bring their own,reusable bags,a policy that a spokesman for the supermarket Giant Food says its chain already has in place.And this policy would be more______(64)if stores imitated furniture mega-retailer Ikea and charged for disposable bags at the checkout counter. A broad ban on the use of plastic shopping bags,which would merely replace some forms of pollution with others,is not the______(65). _________(63)
[多选题]共用题干 The Greatest Mystery of Wha1egThe whale is a warm一blooded,air-breathing animal,giving birth to its young alive,sucking them一and, like all mammals,originated on land. There are many__________(51)of this. Its front flippers (鳍状肢), used for steering and stability,are traces of feet.Immense strength is________(52)into the great body of the big whales,and in fact most of a whale',body is one gigantic muscle.The blue whale'S pulling strength has been estimated________.(53) 400 horsepower. One specimen was reported to have towed(拖)。whaling vessel for seven hours at the _______(54)of eight knot(节).An angry whale will________(55).A famous example of this was the fate of Whaler Essex, ________(56)was sunk off the coast of South America early in the last century.More recently,steel ships have_(57)their plates buckled(使弯曲)in the same way. Sperm whales(抹香鲸)were known to seize the old-time whaleboats in their jaws and crush them.The greatest________(58)of whales is their diving ability.The sperm whale dives to the bottom for his________(59)food,the octopus(章鱼),In that search he is known to go as far down as 3 , 200 feet,where the________(60)is 1,400 pounds,to a square inch.Doing so he will________(61)underwa- ter as long as one hour. Two special skills are involved in this storing up enough________(62)(all whales are air-breathed)and tolerating the great change in pressure.Just how he does it scientists have not _________(63).It is believed that some of the oxygen is stored in a special________(64)of blood vessels,rather than just held in the lungs.And it is believed that a special kind of oil in his head is some sort of a compensating mechanism that_________(65)adjusts the internal pressure of his body.But since you can't bring a live whale into the laboratory for study,no one knows just how these things work. _________(65)
[多选题]共用题干 第三篇Ways to Create Colors in a PhotographThere are two ways to create colors in a photograph.One method called additive,starts with three basic colors and adds them together to produce some other color. The second method,called subtractive,starts with white light(a mixture of all colors in the spectrum)and,by taking away some or all other colors,leaves the one desired.In the additive method,separate colored lights combine to produce various other colors.The three additive primary colors are green,red and blue(each providing about one-third of the wavelengths in the total spectrum).Mixed in varying proportions,they can produce all colors.Green and red light mix to produce yellow,red and blue light mix to produce magenta(a purplish pink);green and blue mix to produce cyan(a bluish green).When equal parts of all three of these primary-colored beams of light overlap(重叠),the mixture appears white to the eye.In the subtractive process colors are produced when dye(染料)absorbs some wavelengths and so passes on only part of the spectrum.The subtractive primaries are cyan,magenta and yellow; these primaries or dyes absorb red,green and blue wavelengths respectively,thus subtracting them from white light. These dye colors are the complementary colors to the three additive primaries of red,green and blue.Properly combined,the subtractive primaries can absorb all colors of light, producing black.But,mixed in varying proportions,they too can produce any color in the spectrum.Whether a particular color is obtained by adding colored lights together or by subtracting some light from the total spectrum,the result looks the same to the eye.The additive process was employed for early color photography. But the subtractive method,while requiring complex chemical techniques,has turned out to be more practical and is the basis of all modern color films. Which of the following is NOT a pair of additive and subtractive primary colors?
[多选题]共用题干 Pathways to Research:Problem-solving1.Pittsburgh's many hills aren't kind to bikers.Anyone hoping to pedal to work there has to contend with steep streets like Canton Avenue,which famously climbs at a nearly 40-degree angle.As a result,some residents avoid biking altogether.2.But University of Pittsburgh graduate Micah Toll,23,and a few friends recently launched an invention that they hope will, increase the city's pedal power:An electric bike called a Pulse PEVO.AM super-strong battery powers the bicycle.Able to hit nearly 20 miles per hour without pedaling,it zips up the city' s most daunting(令人却步的)hills.Toll hopes it will persuade people in Pittsburgh and elsewhere to get out of their cars and onto bikes.3.If it sounds like Toll has a knack(窍门)for fixing problems,that's because he does.In high school,he designed a new type of construction beam.It weighs no more than a feather pillow but can be used to build sturdy(坚固的)homes for refugees fleeing war or natural disaster.For his work , Toll was invited to attend the Intel International Science and Engineering Fair(ISEF)-twice,in 2006 and 2007.The annual competition for young researchers is a program of Society for Science&the Public(that's the parent organization of Science News for Kids).Toll says that when it comes to science,he keeps it simple:"You see a problem and say,‘How could I solve that?’",4.He's not the only one to take that approach.Many young researchers get their start by trying to solve a problem or fulfill a need in their own communities.When students dedicate themselves to finding a solution that may benefit their community , " a passion is ignited,(点燃),"says Wendy Hawkins , executive director of the Intel Foundation,which sponsors Intel ISEF."Finding that passion and fostering it can be the key to many students'future success."she says. Paragraph 4______
[多选题]共用题干 Water and its importance to human life were the center of the world's attention last week. March 22 was World Water Day and______(51)the theme"Water for Life”.There are more than one billion people in the world who live without______(52)drinking water. The United Nations______(53)to cut this number in half by 2015.Solving such a big problem seems like a(n)______(54)challenge.But everyone,even teenagers,can do something to help.A teenage girl in the US has set an example to the______(55)of her age around the world.Rene Haggerty,13,was awarded the 2004 Gloria Barron Prize for her work—_______(56) discarded(废弃的)batteries(电池)which pollute water.In 2003,Haggerty went on a field trip to the Great Lakes Science Centre in Ohio.There she saw an exhibit about how______(57)in old batteries harm the water of Lake Erie.Haggerty learnt that______(58)the batteries was an easy solution."I think everybody can do it,because everyone uses batteries,and it can make a big difference."With these words,she began to.______(59)awareness in her area.She______(60)her county government and school board. She got permission to start a re-cycling program in schools,hospital,churches______(61)the public library. With the help from her family,friends and local waste-management______(62),she gathered containers,arranged transportation,and made an educational video.Over the past two years,she collected four tons of batteries and drew the attention of officials, who were in charge of a battery recycling program but had made______(63)progress.When asked______(64)she feels like a hero,Haggerty is quite modest."Not really. Well,maybe for the fish I saved!"Every year the Gloria Barron Prize is______(65)to young Americans aged 8 to 1 8 who have shown leadership and courage in serving the public and the planet. Each year ten winners receive US MYM 2,000 each,to help with their education costs or their public service work. _________(60)
[多选题]共用题干 Homosexuals(同性恋者)Many homosexuals prefer to be called gay or,for woman,lesbian.Most of them live quiet lives just______(51)anyone else.Some gay people have always raised children,______(52)or with partners,and the use of artificial insemination(人工受精)is increasing among lesbians.Gay persons are in every kind of job.Some are very open about their homosexuality,and some are more private.Some______(53)their sexual orientation as a biological given and others as a choice.For those women who see it as a choice,one reason often given is the inequality in most heterosexual(异性恋的)relationships.Homosexuality has been common in most cultures throughout history and generally______ (54).As a result,homosexual activity became a crime,______(55)which the penalty in early courts was death.Homosexual behavior is still______(56)in many countries and the United States.Homosexuality later came to be viewed widely as less a sin than a sickness,but now no mentalhealth professional(具有专业资格的人)any longer ______ (57) homosexuality an illness. More recent theories to______(58)for homosexuality have included those based on biological and sociological factors.To date.______(59),there is no conclusive general theory that can explain the cause of homosexuality.Attitudes______(60)homosexuality began to change in the second half of the 20th century. Gays attribute this,in part,to their own struggle for their rights and pride in their orientation. Some large companies now______(61)health-care benefits to the life partners of their gay employees. Many cities also have officially appointed lesbian and gay advisory(咨询的)committees.______(62)some attitudes have changed,however,prejudice(偏见)still exists,and in the late 1980s and early 1990s,there were considerable shouts against homosexuals,with attempt to ______(63)laws forbidding the granting of basic civil rights to gays.The AIDS epidemic,which started in the 1980s,has devastated(毁坏)the gay community and brought it together as never before,The organized gay response to the lack of government financial support for fighting AIDS and to the needs of the thousands of AIDS victim______(64)they be gays or not,has been a model of community action.AIDS,however,has also______(65)people with another reason for their prejudice. _________(52)
[多选题]共用题干 So Many"Earths"The Milky Way(银河)contains billions of Earth-sized planets that could support life.That's the finding of a new study.It draws on data that came from NASA's top planet-hunting telescope.A mechanical failure recently put that Kepler space telescope out of service.Kepler had played a big role in creating a census of planets orbiting some 170,000 stars.Its data have been helping astronomers predict how common planets are in our galaxy.The telescope focused on hunting planets that might have conditions similar to those on Earth.The authors of a study,published in The Proceedings of the National Academy of Sciences,conclude that between 14 and 30 out of every 100 stars,with a mass and temperature similar to the Sun,may host a planet that could support life as we know it.Such a planet would have a diameter at least as large as Earth's,but no more than twice that big.The planet also would have to orbit in a star's habitable zone.That's where the surface temperature would allow any water to exist as a liquid.The new estimate of how many planets might fit these conditions comes from studying more than 42,000 stars and identifying suitable worlds orbiting them.The scientists used those numbers to extrapolate(推算) to the rest of the stars that the telescope could not see.The estimate is rough,the authors admit.If applied to the solar system,it would define as habitable a zone starting as close to the Sun as Venus and running to as far away as Mars.Neither planet is Earthlike (although either might have been in the distant past).Using tighter limits,the researchers estimate that between 4 and 8 out of every 100 sunlike stars could host an Earth-sized world.These are ones that would take 200 to 400 days to complete a yearly orbit.Four out of every 100 sunlike stars doesn't sound like a big number.It would mean,however,that the Milky Way could host more than a billion Earth-sized planets with a chance for life. The planet that could support life might be a little bit smaller than Earth.
[多选题]共用题干 The Need to RememberSome people say they have no memory at all:"I just can't remember a thing!"But of course we all have a memory.Our memory tells us who we are.Our memory helps us to make use in the present of what we have learnt in the past.In fact we have different types of memory.For example,our visual memory helps us recall facts and places.Some people have such a strong visual memory that they can remember exactly what they have seen,for example,pages of a book,as a complete picture.Our verbal(言语的)memory helps us remember words and figures we may have heard but not seen or written:Items of a shopping list,a chemical formula,dates,or a recipe.With our emotional(情感的)memory, we recall situations or places where we had; strong feelings,perhaps of happiness or unhappiness. We also have special memories for smell,taste, touch and sound,and for performing physical movements.We have two ways of storing any of these memories. Our short-term memory stores items for up to thirty seconds-enough to remember a telephone number while we dial.Our long-term mem-ory,on the other hand,may store items for a lifetime. Older people in fact have a much biter long-term memory than short-term .They may forget what they have done only a few hours ago,but have the clearest remembrance(记忆)of when they were very young.Psychologists tell us that we only remember a few facts about our past,and that we invent the rest. It is as though we remember only the outline of a story.We then make up the details. We of-ten do this in the way we want to remember them,usually so that we appear as the heroes of our own past , or maybe victims needing sympathy(同情). Visual memory may be used when we read a story.
[多选题]共用题干 Transport and Trade1. Transport is one of the aids to trade.By moving goods from places where they are plentiful to places where they are scarce,transport adds to their value.The more easily goods can be brought over the distance that separates producer and consumer,the better for trade.When there were no railways,no good roads,no canals,and only small sailing ships,trade was on a small scale.2. The great advances made in transport during the last two hundred years were accompanied by a big increase in trade.Bigger and faster ships enabled a trade in meat to develop between Britain and New Zealand,for instance.Quicker transport makes possible mass-production and big business,drawing supplies from,and selling goods to,all parts of the globe.Big factories could not exist without transport to carry the large number of workers they need to and from their homes. Big city stores could not have developed unless customers could travel easily from the suburbs and goods were delivered to their homes.Big cities could not survive unless food could be brought from a distance.3. Transport also prevents waste.Much of the fish landed at the ports would be wasted if it could not be taken quickly to inland towns.Transport has given us a much greater variety of foods and goods since we no longer have to live on what is produced locally.Foods which at one time could be obtained only during a part of the year can now be obtained all through the year. Transport has raised the standard of living.4. By moving fuel,raw materials,and even power,for example,through electric cables,transport has led to the establishment of industries and trade in areas where they would have been impossible before. Districts and countries can concentrate on making things which they can do better and more cheaply than others and can then exchange them with one another. The cheaper and quicker transport becomes,the longer the distance over which goods can profitably be earned. Countries with poor transport have a lower standard of living.5. Commerce requires not only the moving of goods and people but also the carrying of messages and information .Means of communication,like telephones,cables and radio,send information about prices,supplies,and changing conditions in different parts of the world. In this way,advanced communication systems also help to develop trade. Paragraph 4______
[多选题]共用题干 Changes in MuseumsMuseums have changed.They are no longer places that one"should"visit;they are places to enjoy and learn.At a science museum in Ontario,Canada,you can feel your hair stand on end as harmless electricity passes through your body.At the Metropolitan(大城市的)Museum of Art in New York City , you can look at the seventeenth century instruments while listening to their music.At New York's American Museum of Natural History recently,you can help make a bone-by- bone reproduction of the museum's dinosaur(恐 龙),a beast that lived 200 million years ago.More and more museum directors are realizing that people learn best when they can somehow become part of what they are seeing.In many science museums,for example,there are no guided tours.The visitor is encouraged to touch,listen,operate,and experiment so as to discover scientific principles for himself. The purpose is not only to provide fun but also to help people feel at home in the world of science.The theory is that people who do not understand science will probably fear it,and those who fear science will not use it to best advantage.One cause of all these changes is the increase in wealth and leisure time.Another cause is the rising percentage of young people in the population.Many of these young people are college students or college graduates.Leon F.Twiggs,a young black professor of art once said,"They see things in a new and different way.They are not satisfied to stand and look at works of art;they want art they can participate(参加)in."The same is true of science and history. New York's American Museum of Natural History is opened recently.
[多选题]共用题干 第三篇Up in SmokeI began to smoke when I was in high school. In fact,I remember the evening I was at a girlfriend's house,and we were watching a movie一a terribly romantic movie.He(the hero of the movie)was in love,she(his lady)was beautiful,and they were both smoking. My friend had only two cigarettes from a pack in her mother's purse,and she gave one to me.It was my first time.My parents didn't care much. They both smoked,and my older brother did too. My mother told me that smokers don't grow tall,but I was already 5 '6"(taller than most of the boys in my class), so I was happy to hear that"fact".In school,the teachers talked against smoking,but the cigarette advertisements were so exciting. The men in the ads were so good-looking and so successful,and the women were well, they were beautiful and sophisticated(老于世故的).I read a book called How to Stop Smoking. The writer said that smoking wastes time,and that cigarettes cost a lot of money."So what?"I thought. The book didn't say that smoking can take away years of your life.But ten years later,everyone began to hear about the negative effects of cigarette smoke:lung disease,cancer,and heart problems.After that,there was a health warning on every pack of cigarettes.I didn't pay much attention to the reports and warnings.I felt healthy,and thought I was taking good care of myself.Then two events changed my mind.First,I started to cough,I thought it was just a cold,but it.didn't get better. Second,my brother got lung cancer. He got sicker and sicker. My brother and I used to smoke cigarettes together over twenty years ago,and we smoked our last cigarettes together the day before he died,I sat with him in his hospital room,and I decided to quit."NO more cigarettes,ever,"I said to myself.However,it was very hard to stop.Nicotine(尼古丁)is a drug;as a result,cigarettes cause a powerful addiction.I tried several times to quit on my own一wlthout success.I made excuses,I told myself:Smoking helps me keep my figure一I don,t gain weight when I smoke.Smoking not only relaxes me but it also helps me think clearly.I,m a free,liberated woman,I can smoke when I want to.Finally,I ran out of excuses一I might say my excuses went up in smoke.I joined the"Stop Smoking"program at the local hospital,which also ended up in failure. The book called How to Stop Smoking______.
[多选题]共用题干 What is the Coolest Gas in the Universe?What is the coldest air temperature ever recorded on Earth?Where was this low temperature recorded ?The coldest recorded temperature on Earth was -91℃, which_____ (51) in Antarctica(南极洲) in 1983.We encounter an interesting situation when we discuss temperatures in_________(52).Temperatures in Earth orbit(轨道)actually range from about +120℃ to -120℃. The temperature depends upon ______(53)you are in direct sunlight or in shade.Obviously,-120℃ is colder than our body can ________ (54)endure.The space temperatures just discussed affect only our area of the solar________(55).Obviously,it is hotter closer to the Sun and colder as we travel__________(56)from the Sun,Scientigtg egtimate tern- peratures at Pluto are about -210℃.How cold is the lowest estimated temperature in the entire universe?Again,it depends upon your_________(57).We are taught it is supposedly__________(58)to have atemperature below absolute zero,which is-273℃,at which atoms do not move.Two scientists,Cornell and Wieman,have successfully______(59)down a gas to a temperature barely above absolute zero. They won a Nobel Prize in Physics in 2001 for their work一not a discovery in this case.Why is the two scientists'work so important to science?In the 1920s,Satyendra Nath Bose was studying an interesting_______(60)about special light par-tidles(微粒)we now call photons(光子).Bose had trouble __________(61)other scientists to believe his theory,so he contacted Albert Einstein. Einstein’s calculations helped him theorize that atoms_______(62) behave as Bose thought一but only at very cold temperatures.Scientists have also discovered that ultra-cold(超冷)atoms can help them make the world'S atomic clocks even__________(63)accurate.These clocks are so accurate today they would oniy lose one second _________ (64)six million years!Such accuracy will help us travel in space because digtanee is velocity(速度)times time( d=vt).With the long distances involved in space _______(65),we need to know time as accurately as possibie to get accurate distance. _________(52)
[多选题]共用题干 Computer Mouse The basic computer mouse is______(51)amazingly clever invention with a relatively simple design that allows us to point at things on the computer and it is very productive.Think of all the things you can do with a mouse like selecting text for copying and pasting , drawing , and even scrolling(滚动)on the page with the newer mice with the wheel.Most of us use the computer mouse daily without stopping to think how it______(52)until it gets dirty and we have to learn how to______(53)it.We learn to point at things______(54)we learn to speak,so the mouse is a very natural pointing device.Other computer pointing devices include light pens,graphics tablets and touch screens,but the mouse is still our workhorse. The computer mouse was_____(55)in 1964 by Douglas Englehart of Stanford University.As computer screens became more popalar and arrow keys were used to move around a body of text,it became clear that a pointing device that allowed easier motion through the text and even selection of text would be very useful.The introduction of the mouse,with the Apple lisa computer in 1983,really started the computer public on the road to relying on the mouse_____(56)routine computer tasks. How does the mouse work?We have to start at the bottom,so think upside down for now.It all starts with the mouse ball.As the mouse ball in the bottom of the mouse rolls over the mouse pad,it presses against and turns two shafts(轴).The shafts are connected to wheels with several small holes in them.The wheels have a pair of small electronic light-emitting devices______(57) light-emitting diodes(LED)mounted on either side.One LED sends a light beam to the LED on______(58)side.As the wheels spin and a hole rotates by,the light beam gets through to the LED on the other side.But a moment______(59)the light beam is blocked until the next hole is in place.The LED______(60)a changing pattern of light, converts the pattern______(61)an electronic signal,and sends the signal to the computer through wires in a cable that goes out of the mouse body.This cable is the tail that helps give the mouse its name.The computer interprets the signal to tell it where to position the cursor on the computer______(62). So far we have only discussed the basic computer mouse that______(63)of you probably have or have used.One problem with this design is that the mouse gets dirty as the ball rolls over the surface and picks up dirt.______(64)you have to clean your mouse.The newer optical mice______(65)this problem by having no moving parts. 55._________
[多选题]共用题干 The Greatest Mystery of Wha1egThe whale is a warm一blooded,air-breathing animal,giving birth to its young alive,sucking them一and, like all mammals,originated on land. There are many__________(51)of this. Its front flippers (鳍状肢), used for steering and stability,are traces of feet.Immense strength is________(52)into the great body of the big whales,and in fact most of a whale',body is one gigantic muscle.The blue whale'S pulling strength has been estimated________.(53) 400 horsepower. One specimen was reported to have towed(拖)。whaling vessel for seven hours at the _______(54)of eight knot(节).An angry whale will________(55).A famous example of this was the fate of Whaler Essex, ________(56)was sunk off the coast of South America early in the last century.More recently,steel ships have_(57)their plates buckled(使弯曲)in the same way. Sperm whales(抹香鲸)were known to seize the old-time whaleboats in their jaws and crush them.The greatest________(58)of whales is their diving ability.The sperm whale dives to the bottom for his________(59)food,the octopus(章鱼),In that search he is known to go as far down as 3 , 200 feet,where the________(60)is 1,400 pounds,to a square inch.Doing so he will________(61)underwa- ter as long as one hour. Two special skills are involved in this storing up enough________(62)(all whales are air-breathed)and tolerating the great change in pressure.Just how he does it scientists have not _________(63).It is believed that some of the oxygen is stored in a special________(64)of blood vessels,rather than just held in the lungs.And it is believed that a special kind of oil in his head is some sort of a compensating mechanism that_________(65)adjusts the internal pressure of his body.But since you can't bring a live whale into the laboratory for study,no one knows just how these things work. _________(63)
[多选题]共用题干 Earthquake Insurance1.Earthquake insurance is a form of homeowners' insurance which deals with damage caused by earthquakes.In regions where earthquakes are especially common,homeowners may be required to carry earthquake insurance,so that in the event of an earthquake,people rely less on government disaster funds and more on their own insurance policies.As a general rule,earthquake insurance is not a part of standard insurance policies,and it must be purchased separately.2.Earthquakes can cause a variety of damage to a home,ranging from complete destruction to damage which causes the building to become structurally unsound.Indirect damage caused by neigh-boring collapses of structures and freeways can also occur,as can more bizarre forms of earthquake damage,like winding up with a car in the living room or a sinkhole in the back yard.Fires and flooding are also common problems in the wake of earthquakes.3.When homeowners purchase earthquake insurance,they may be protected against both direct damage,such as a structural collapse after an earthquake,and indirect damage,like a fire caused by broken gas lines.More commonly,the insurance only covers structural damage caused directly by the earthquake.The insurance may pay for a complete replacement of the structure,or a remodel, depending on the type of insurance and the nature of the damage.Some policies also cover damaged property like cars,and they may provide living allowances so that the residents of the home can temporarily relocate for the duration of the repairs.4.This type of homeowners' insurance is prone to adverse selection,in which only people in high risk areas purchase the insurance.The problem with adverse selection for insurance companies is that it decreases the pool of customers,making potential payouts very expensive.For this reason, earthquake insurance often has a high deductible,and it can he very expensive.5.Recognizing the need for earthquake insurance,some governments have provided subsidies for earthquake insurance,to reduce the stress on insurance companies.Insurance companies also adjust their risk pools carefully,and there may be stringent requirements for a homeowner to purchase earthquake insurance.For example,a home may need to be retrofitted for earthquake safety, reducing the amount of damage which will be incurred in a quake.For low-income home owners, this can be very difficult,as it drives the cost of earthquake insurance out of reach,which can in turn make it difficult to get home loans,as many banks in earthquake-prone areas insist on earth-quake insurance as a condition for a loan. Paragraph 1______
[多选题]共用题干 Animal's"Sixth Sense"A tsunami was triggered by an earthquake in the Indian Ocean in December,2004.It killed tens of thousands of people in Asia and East Africa. Wild animals,______(51),seem to have escaped that terrible tsunami .This phenomenon adds weight to notions that they possess a"sixth sense"for______(52),experts said.Sri Lankan wildlife officials have said the giant waves that killed over 24,000 people along the Indian Ocean island's coast clearly______(53)wild beasts,with no dead animals found."No elephants are dead,not______(54)a dead mbbit. I think animals can______(55)dis-aster. They have a sixth sense.They know when things are happening,"H. D. Ratnayake,deputy director of Sri Lanka's Wildlife Department,said about one month after the tsunami attack. The______(56) washed floodwatei up to 2 miles inland at Yala National Park in the ravaged southeast,Sri Lanka's biggest wildlife______(57)and home to hundreds of wild elephants and several leopards."There has been a lot of apparent evidence about dogs barking or birds migrating______(58)volcanic eruptions or earthquakes. But it has not been proven,"said Matthew van Lierop,an animal behavior______(59)at Johannesburg Zoo."There have been no______(60)studies because you can't really test it in a lab or field setting,"he told Reuters.Other authorities concurred with this______(61)."Wildlife seem to be able to pick up certain______(62),especially birds... there are many reports of birds detecting impending disasters,"said Clive Walker,who has written several books on African wildlife.Animals certainly______(63)on the known senses such as smell or hearing to avoid dan-ger such as predators.The notion of an animal"sixth sense”-or______(64)other mythical power-is an endur-ing one which the evidence on Sri Lanka's ravaged coast is likely to add to.The Romans saw owls______(65)omens of impending disaster and many ancient cul- tures viewed elephants as sacred animals endowed with special powers or attributes. 65._________
[多选题]共用题干 The History of the Fridge 1 The fridge is considered a necessity.It has been so since the l960s when packaged food first appeared with the label:"store in the refrigerator." 2 In my fridgeless fifties childhood,I was fed well and healthily.The milkman came daily,the grocer, the butcher,the baker,and the ice-cream man delivered two or three times a week.The Sunday meat would last until Wednesday and surplus bread and milk became all kinds of cakes.Nothing was wasted and we were never troubled by rotten food.Thirty years on,food deliveries have ceased,fresh vegetables are almost unobtainable in the country. 3 The invention of the fridge contributed comparatively little to the art of food preservation.A vast variety of well-tried techniques already existed-natural cooling,drying'smoking'salting'sugaring,bottling… 4 What refrigeration did promote was marketing-marketing hardware and electricity,marketing soft drinks,marketing dead bodies of animals around the globe in search of。good price. 5 Consequently,most of the world's fridges are to be found,not in the tropics where they might prove useful,but in the wealthy countries with mild temperatures where they are climatically almost unnecessary.Every winter,millions of fridges hum away continuously and at vast expense,busily maintaining an artificially-cooled space inside an artificially-heated house-while outside,nature provides the desired temperature free of charge. 6 The fridge's effect upon the environment has been evident,while its contribution to human happiness has been insignificant.If you don't believe me,try it yourself.Invest in。food cabinet(橱柜)and turn off your fridge next winter.You may miss the hamburgers but at least you’ll get rid of that terrible hum. Paragraph 2______
[多选题]共用题干 Please Fasten Your SeatbeltsSevere turbulence(湍流)can kill aircraft passengers.Now,in test flights over the Rocky Mountains, NASA(美国航空航天局)engineers have successfully detected clear-air turbulence up to 10 seconds before an aircraft hits it.Clear-air turbulence often catches pilots by surprise.Invisible to radar,it is difficult to forecast and can hurl(用力抛出去)passengers about the cabin.In December 1997 , one passenger died and a hundred others were injured when unexpected rough air caused a United Airlines flight over the Pacific to drop 300 meters in a few seconds.However,passengers can avoid serious injury by fastening their seatbelts."It is the only antidote(对 策)for this sort of thing,"says Rod Bogue, project manager at NASA's Dryden Flight Research Center in Edwards,California.The Center's new turbulence detector is based on lidar,or laser-radar.Laser pulses are sent ahead of the plane and these are then reflected back by particles in the air.The technique depends on the Doppler Effect(多普勒效应).The wavelength of the light shifts according to the speed at which the particles are approaching.In calm air,the speed equals the plane's airspeed.But as the particles swirl(打漩) in rough air,their speed of approach increases or decreases rapidly.The rate of change in speed corresponds to the severity(激烈程度)of the turbulence.In a series of tests that began last month,a research jet flew repeatedly into、 disturbed air over the mountain ridges(山脉)near Pueblo , Colorado.The lidar detector spotted turbulence between 3 and 8 kilometers ahead, and its forecasts of strength and duration corresponded closely with the turbulence that the plane encountered.Bogue says that he had"a comfortable amount of time"to fasten his seatbelt.The researchers are planning to improve the lidar's range with a more powerful beam.The system could be installed on commercial aircraft in the next few years. The turbulence detector can tell the severity of the turbulence by measuring______.
[多选题]共用题干 Changes in MuseumsMuseums have changed.They are no longer places that one"should"visit;they are places to enjoy and learn.At a science museum in Ontario,Canada,you can feel your hair stand on end as harmless electricity passes through your body.At the Metropolitan(大城市的)Museum of Art in New York City , you can look at the seventeenth century instruments while listening to their music.At New York's American Museum of Natural History recently,you can help make a bone-by- bone reproduction of the museum's dinosaur(恐 龙),a beast that lived 200 million years ago.More and more museum directors are realizing that people learn best when they can somehow become part of what they are seeing.In many science museums,for example,there are no guided tours.The visitor is encouraged to touch,listen,operate,and experiment so as to discover scientific principles for himself. The purpose is not only to provide fun but also to help people feel at home in the world of science.The theory is that people who do not understand science will probably fear it,and those who fear science will not use it to best advantage.One cause of all these changes is the increase in wealth and leisure time.Another cause is the rising percentage of young people in the population.Many of these young people are college students or college graduates.Leon F.Twiggs,a young black professor of art once said,"They see things in a new and different way.They are not satisfied to stand and look at works of art;they want art they can participate(参加)in."The same is true of science and history. In science museums nowadays visitors are not allowed to touch or operate the objects on display.

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