理工A

考试试题

[多选题]共用题干 第一篇The Northern LightsThe sun is stormy and has its own kind of weather.It is so hot and active that even the Sun's gravity cannot hold its atmosphere in check!Energy flows away from the Sun toward the Earth in a stream of electrified particles that move at speeds around a million miles per hour.These particles are called plasma (等离子体),and the stream of plasma coming from the Sun is called the solar wind.The more active the Sun,the stronger the solar wind.The solar wind constantly streams toward the Earth,but don't worry because a protective magnetic field surrounds our planet.The same magnetic field that makes your compass point north also steers the particles from the Sun to the north and south poles.The charged particles become trapped in magnetic belts around the Earth.When a large blast of solar wind crashes into the Earth's magnetic field,the magnetic field first gets squeezed and then the magnetic field lines break and reconnect.The breaking and reconnecting of the magnetic field lines can cause atomic particles called electrons trapped in the belts to fall into tile Earth's atmosphere at the poles.As the electrons fall to the Earth,they collide with gas molecules in the atmosphere,creating flashes of light in the sky.Each atmospheric gas glows a different color.Oxygen and nitrogen glows red and green arid nitrogen glows violet purple.As these various colors glow and dance in the night sky,they create the Northern Lights and the Southern Lights.Watching auroras(北极光)is fun and exciting, but normally you can only see them in places far north like Alaska and Canada.The movement of the aurora across the sky is usually slow enough to easily follow with your eyes but they can also pulsate(跳动),flicker(闪烁),or even move like waves.During solar maximum,5 auroras are seen as far south as Florida,even Mexico!Auroras often seem to be very close to the ground,but the lowest aurora is still about 100 kilometers above the ground,a distance much higher than clouds are formed or airplanes can fly.A typical aurora band can be thousands of kilometers long,a few hundred kilometers high,but only a few hundred meters thick.We hope you are able to travel to far north places like the Arctic Circle and see the Northern Lights at least once during your lifetime.We know you will never forget it! The solar wind comes into being as a result of_______.
[多选题]共用题干 Toads are Arthritic and in PainArthritis(关节炎)is an illness that can cause pain and swelling in your bones. Toads(蟾蜍),a big problem 'in the north of Australia,are suffering from painful arthritis in their legs and backbone,a new stu街has shown. The toads that jump the fastest are more likely to be larger and to have longer legs.______(46)The large yellow toads,native to South and Central America,were introduced into the north-eastern Aus- tralian state of Queensland in 1935 in an attempt to stop beetles and other insects from destroying sugarcane crops.Now up to 200 million of the poisonous toads exist in the country,and they are rapidly spreading through the state of Northern Territory at a rate of up to 60 km a year. The toads can now be found across more than one million square kilometres.________(47)A Venezuelan poison virus was tried in the 1990s but had to be abandoned after it was found to also kill native frog species.The toads have severely affected ecosystems in Australia. Ariinials,arid sometimes pets,that eat the toads die im- mediately from their poison,and the toads themselves eat anything they can fit inside their mouth._________(48)A co-author of the new study,Rick Shine,a professor at the University of Sydney,says that little atten- tion has been given to the problems that toads face.Rick and his colleagues studied nearly 500 toads from Queensland and the Northern Territory and found that those in the latter state were very different.They were active,sprinting down roads and breeding quickly.According to the results of the study,the fastest toads travel nearly one kilometre a night._________(49) But speed and strength come at a price一arthritis of the legs and backbone due to constant pressure placed on them.In laboratory tests,the researchers found that after about 15 minutes of hopping,arthritic toads wouldtravel less distance with each hop(跳跃).________(50)These toads are so programmed to move, apparently,that even when in pain the toads travelled as fast and as far as the healthy ones,continuing their constant march across the landscape. __________(49)
[多选题]共用题干 Science and Truth“FINAGLE”(欺骗)is not a word that most people associate with science. One reason is that the image of the scientist is of one who always______ (51)data in an impartial(不偏不倚的)search for truth. In any debate______ ( 52 ) intelligence , schooling , energy—the phrase“science says”usually disarms opposition.But scientists have long acknowledged the existence of a“finagle factor”—a tendency by many scientists to give a helpful change to the data to______(53)desired results.The latest of the finagle factor in action comes from Stephen Jay Gould,a Harvard biologist,who has ______(54)the important 19th century work of Dr. Samuel George Morton.Morton was fa-mous in his time for analysing the brain______(55)of the skulls as a measure of intelligence.He concluded that whites had the largest brains,that the brains of Indians and blacks were smaller,and______(56),that whites constitute a superior race.Gould went back to Morton's original data and concluded that the______(57)were an example of the finagle at work .He found that Morton's“discovery”was made by leaving out embarrassing data,______(58)incorrect procedures,and changing his criteria-again,always in fayour of his argument. Morton has been thoroughly discredited by now and scientists do not believe that brain size reflects______(59).But Gould went on to say Morton's story is only an example of a common problem in ______(60)work .Some of the leading figures in science are______(61)to have used the finagle factor. Gould says that Isaac Newton fudged out(捏造)to support at least three central statements that he could not prove .And so______(62)Laudius Ptolemy,the Greek astronomer,whose master work,Almagest,summed up the case for a solar system that had the earth asits centre .Recent______(63)indicate that Ptolemy either faked some key data or resorted heavily to the finagle factor.All this is important because the finagle factor is still at work.For example,in the artificial sweetener controversy,it is______(64)that all the studies sponsored by the sugar industry find that the artificial sweetener is unsafe,______(65)all the studies sponsored by the diet food industry find nothing wrong with it. 62._________
[多选题]共用题干 Science and Truth“FINAGLE”(欺骗)is not a word that most people associate with science. One reason is that the image of the scientist is of one who always______ (51)data in an impartial(不偏不倚的)search for truth. In any debate______ ( 52 ) intelligence , schooling , energy—the phrase“science says”usually disarms opposition.But scientists have long acknowledged the existence of a“finagle factor”—a tendency by many scientists to give a helpful change to the data to______(53)desired results.The latest of the finagle factor in action comes from Stephen Jay Gould,a Harvard biologist,who has ______(54)the important 19th century work of Dr. Samuel George Morton.Morton was fa-mous in his time for analysing the brain______(55)of the skulls as a measure of intelligence.He concluded that whites had the largest brains,that the brains of Indians and blacks were smaller,and______(56),that whites constitute a superior race.Gould went back to Morton's original data and concluded that the______(57)were an example of the finagle at work .He found that Morton's“discovery”was made by leaving out embarrassing data,______(58)incorrect procedures,and changing his criteria-again,always in fayour of his argument. Morton has been thoroughly discredited by now and scientists do not believe that brain size reflects______(59).But Gould went on to say Morton's story is only an example of a common problem in ______(60)work .Some of the leading figures in science are______(61)to have used the finagle factor. Gould says that Isaac Newton fudged out(捏造)to support at least three central statements that he could not prove .And so______(62)Laudius Ptolemy,the Greek astronomer,whose master work,Almagest,summed up the case for a solar system that had the earth asits centre .Recent______(63)indicate that Ptolemy either faked some key data or resorted heavily to the finagle factor.All this is important because the finagle factor is still at work.For example,in the artificial sweetener controversy,it is______(64)that all the studies sponsored by the sugar industry find that the artificial sweetener is unsafe,______(65)all the studies sponsored by the diet food industry find nothing wrong with it. 58._________
[多选题]共用题干 The Impact of Antarctic Ozone HoleThe Antarctic ozone(臭氧)hole is changing weather patterns across the Southern Hemisphere (半球),even affecting the tropics,scientists have concluded. The scientists______(51)the new study added the ozone hole into standard climate models to_______(52)how it might have affected winds and rains. They say rainfall has moved further south towards the pole and the effect has been_______(53)strong over Australia.And of_______(54)interest was the southward of the Southern Hemisphere jet stream. These high一altitude winds are_______(55)to determining weather patterns,in both hemispheres. Much of the cold weather felt in the UK_______(56)the last couple of winters,for example,was caused by blocking of the Northern Hemisphere stream.The team found that overall,the ozone hole has_______(57)in rainfall moving south along with the winds._______(58)there are regional differences,particularly concerning Australia. In terms of the average for that zone,the ozone hole_______(59)about a 10% change一but for Australia,it's about 35%.Their modeling indicated that global warming_______(60)greenhouse gas emissions is also a factor in changing rainfall patterns.Natural climate cycles are also thought to be important here,as different rainfall patterns were _______(61)in the era before ozone depletion(消耗)and late 20th Century warming.Although the_______(62)international organization has significantly checked emissions of harmful substances,they_______(63)for decades in the atmosphere,and so their effects are still being felt.Earlier,and international organization forecast that even the Antarctic ozone hole一which is more severe than its_______(64)in the Northern Hemisphere一should be_______(65)by 2045—2060. _________(60)
[多选题]共用题干 Better Solar Energy Systems:More Heat,More LightSolar photovoltaic(光电的)thermal energy systems , or PVTs , generate both heat and electricity , but _________ (51)now they haven't been very good at the heat-generating part compared to a stand-alone solar thermal collector. That ' s because they operate at low temperatures to cool crystalline silicon(晶体硅)solar cells, _______(52)lets the silicon generate more electricity but isn't a very efficient way to gather heat.That's a problem of economics.Good solar hot-water systems can harvest much more energy than asolar一electric system at a substantially lower _________(53).And it's also a space problem:photovoltaiccells can_________(54)up all the space on the roof,leaving little room for thermal applications.In a pair of studies,Joshua Pearce,an associate professor of materials science and engineering,has de- vised a_________(55)in the form of a better PVT made with a different kind of silicon.Most solar panels are made with crystalline silicon,but you can also make solar cells out of amorphous(非晶形的)silicon , commonly known________( 56 ) thin-film silicon. They don ' t create as much elec-tricity,but they are lighter,flexible,and cheaper. And,because they________(57)much less silicon,they have a greener footprint._________(58),thin-film silicon solar cells are vulnerable to some bad一news physics in the form of the Staebler-Wronski effect."That means that their efficiency drops when you_________(59)them to light一pretty much the worst possible effect for a solar cell,"Pearce explains,which is one of the__________(60)thin-film solar panels make up only a small fraction of the market.However,Pearce and his team found a_______(61)to engineer around the Staebler-Wronski effect by incorporating thin-film silicon in a new________(62)of PVT. You don't have to cool down thin-film sili- con to make it work.In fact,Pearce's group discovered that by heating it to solar-thermal operating tempera- tures,near the boiling_________(63)of water,they could make thicker cells that largely_________(64) the Staebler-Wronski effect.When they applied the thin-film silicon directly to a solar thermal energy collector, they also found that by baking the cell once a day,they_________(65)the solar cell's electrical efficiency by over 10 percent. _________(64)
[多选题]共用题干 A Special JourneyI am often asked to describe the experience of_______(51)a child with a disability一to try to help people who have not shared that unique experience to understand it,to imagine how it would feel.It's like this…_______(52)you're going to have a baby,it's like planning a fabulous vacation trip to Italy. You buy a bunch of guide books and make your wonderful_______(53).The Coliseum,the Michelangelo,David,the gondolas in Venice.You may learn some handy phrases in Italian. It's all very exciting.After months of eager anticipation,the day finally_______(54).You pack your bags and _______(55)you go.Several hours later,the plane lands.The_______(56)comes in and says,"Welcome to Holland.""Holland?"you say."What do you mean by Holland?I signed up for Italy!I'm supposed to be in Italy. All my life I've dreamed_______(57)going to Italy."But there's been a change in the flight plan.They've landed in Holland and there you must stay.The important thing is that they haven't taken you to a horrible,disgusting,filthy place,full of pestilence,_______(58)and disease.It's just a_______(59)place._______(60)you must go out and buy new guide books.And you must learn a whole new language.And you will meet a whole new group of people you would never have met.It's just a different place.It's slower-paced than Italy,less flashy than Italy. But after you've been there for a while and you catch your breath,you look around…and you begin to_______ (61)that Holland has windmills…and Holland has tulips.Holland even has Rembrandts.But everyone you know is busy coming and going_______(62)Italy…and they're all bragging about_______(63)a wonderful time they had there. And for the rest of your life,you will say"Yes,that's where I was_______(64)to go.That's what I had planned."But if you spend your life_______(65)the fact that you didn't get to Italy,you may never be free to enjoy the very special,the very lovely things about Holland. _________(65)
[多选题]共用题干 A Heroic WomanThe whole of the United States cheered its latest hero,Ashley Smith,with the Federal Bureau of investigation saying it was planning to give a big reward to her for having a brave heart and wise mind.______(46)She was moving into her apartment in Atlanta,Georgia early on the morning of March 12,when a man followed her to her door and put a gun to her side."I started walking to my door,and I felt really,really afraid,"she said in a TV interview last week.The man was BrianNichols , 33 . He was suspected of killing three people at an Atlanta courthouse(法院)on March 11 and later of killing a federal agent.______(47)Nichols tied Smith up with tape,but released her after she repeatedly begged him not to take her life."I told him if he hurt me,my little girl wouldn't have a mummy",she said.In order to calm the man down,she read to him from"The Purpose-Driven Life",a best-selling religious book.He asked her to repeat a paragraph about"what you thought your purpose in life was,what talents were you given.______(48)"I basically just talked to him and tried to gain his trust."Smith said.Smith said she asked Nichols why he chose her. He said he thought"I was an angel sent from God,and we were Christian sister and brother",she said,"And that he was lost,and that God led him to me to tell him that he had hurt a lot of people."______(49)She said Nichols was surprised when she made him breakfast and that the two of them watched television coverage(报道) of the police hunt for him."I cannot believe that's me."Nichols told the woman.Then,Nichols asked Smith what she thought he should do.She said,"I think you should turn yourself in.If you don't,lots more people are going to get hurt."Eventually,he let her go.______(50)A US $ 60,000 reward had been posted for Nichols' capture. Authorities said they did not yet know if Smith would be eligible(有资格的)for that money. ______(49)
[多选题]共用题干 Will We Take Vacation in Spaces?When Mike Kelly first set out to build his own private space-ferry service,he figured his bread-and-butter business would be lofting satellites into high-Earth orbit. Now he thinks he may have figured wrong.“People were always asking me when they could go,”says Kelly,who runsKelly Space TechnologT out of San Bernardino,Californi a.“I realized that real market is in space tourism.”According to preliminary market surveys,there are 10,000 would-be-space-tourists willing to spend $1 million each to visit the final frontier. Space Adventure in Arlington,Virginia,has taken more than 1 30 deposits for a two-hour,$98,000 space tour tentatively(and somewhat dubiously)set to occur by 2005 .Gene Meyers of the Space Island Group says:“Space is the next exotic vacation spot.”This may all sound great,but there are a few hurdles.Putting a simple satellite into orbit with no oxygen,life support or return trip necessary already costs an astronomical $22,000/kg.And that doesn't include the cost of insuring rich and possibly litigious passenger. John Pike of theFederation of American Scientists acerbically suggests that the entire group of entrepreneurs trying to corner the space tourism market have between them“just enough money to blow up one rocket.”The U .S.space agency has plenty of money but zero interest in making space less expensive for the little guys.So the little guys are racing to do what the government has failed to do:design a reusable launch system that's inexpensive,safe and reliable.Kelly Space's prototype looks like a plane that has sprouted rocket engines.Rotary Rocket in Redwood City,California,hasa booster with rotors make a helicopter-style return to Earth;Kistler Aerospace in Kirkland,Wash- ington,is piecing together its versions from old Soviet engines,shuttle-style thermal protection tiles and an elaborate parachute system.The first passenger countdowns are still years away,but bureaucrats at the Federal Aviation Administration in Washington are already informally discussing flight regulations.After all,you can't be too prepared for a trip to that galaxy far,far away.For those who are intent on joining the 100-mile high club,Hilton and Budget are plotting to build space hotels.Before the Russian space Mir came down,some people were talking about using it as a low-rent space hotel to reduce the cost. If a space hotel is finally built in space,and if you're thinking of staying in it,you may want to check the Michelin ratings before booking yourself a suite. Kelly hoped to develop space tourism,which he thought would be a good market.
[多选题]共用题干 第三篇The Age of being Bullied and Its EffectThe age at which kids first fall victim to bullying(欺辱)could influence how strongly they are affected,suggests a new study.And,surprisingly,it is not the youngest kids who are hurt the most in the long term. Bullying can have long-lasting effects,but particularly when it begins in adolescence(青春期),the researchers say.People subjected to either oral or physical bullying are known to be at greater risk for developing depression,anxiety disorders or to behave violently.But not everyone reacts in this way.Children bullied for the first time before their adolescence seem to get over it,but those who are victimized for the first time late on in adolescence seem to become more aggressive or are more likely to turn to drink as a means of coping. These are the conclusions of psychologist Matthew Newman and his colleagues from the University of Texas at Austin,U.S.The team gave questionnaires to nearly 1,500 college students regarding their experience of physical and psychological bullying before adolescence一before high school一and in late adolescence一at high school.They assessed mood and mental state,judging by signs of anxiety or depression,such as sleeplessness.The group was also questioned about how they would react to certain challenges,such as being embarrassed or provoked.People who were bullied all revealed slightly higher levels of stress.But while those bullied earlier in life seemed to respond normally to provocation,people bullied for the first time late in adolescence are more withdrawn and sensitive to violence.The best solution was strong social support,whether from friends,family or school.Those with no one to share their problems were suffered the most.So perhaps it is best not to shelter children completely from bullying early on,suggests Newman."They may get stressed,but unhealthy coping really jumps out when they are bullied for the first time later on."The effects are likely to be related to the developing stress hormone system, which matures during adolescence,he concludes.Studies show abnormal stress responses in adult animals that experience social stress or aggression from other animals during adolescence.
[多选题]共用题干 Toads are Arthritic and in PainArthritis(关节炎)is an illness that can cause pain and swelling in your bones. Toads(蟾蜍),a big problem 'in the north of Australia,are suffering from painful arthritis in their legs and backbone,a new stu街has shown. The toads that jump the fastest are more likely to be larger and to have longer legs.______(46)The large yellow toads,native to South and Central America,were introduced into the north-eastern Aus- tralian state of Queensland in 1935 in an attempt to stop beetles and other insects from destroying sugarcane crops.Now up to 200 million of the poisonous toads exist in the country,and they are rapidly spreading through the state of Northern Territory at a rate of up to 60 km a year. The toads can now be found across more than one million square kilometres.________(47)A Venezuelan poison virus was tried in the 1990s but had to be abandoned after it was found to also kill native frog species.The toads have severely affected ecosystems in Australia. Ariinials,arid sometimes pets,that eat the toads die im- mediately from their poison,and the toads themselves eat anything they can fit inside their mouth._________(48)A co-author of the new study,Rick Shine,a professor at the University of Sydney,says that little atten- tion has been given to the problems that toads face.Rick and his colleagues studied nearly 500 toads from Queensland and the Northern Territory and found that those in the latter state were very different.They were active,sprinting down roads and breeding quickly.According to the results of the study,the fastest toads travel nearly one kilometre a night._________(49) But speed and strength come at a price一arthritis of the legs and backbone due to constant pressure placed on them.In laboratory tests,the researchers found that after about 15 minutes of hopping,arthritic toads wouldtravel less distance with each hop(跳跃).________(50)These toads are so programmed to move, apparently,that even when in pain the toads travelled as fast and as far as the healthy ones,continuing their constant march across the landscape. __________(48)
[多选题]共用题干 The Fridge1.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一natural cooling,drying,smoking,slating, sugaring,bottling…4.What refrigeration did promote was marketing一marketing hardware and electricity,marketing soft drinks,marketing dead bodies of animals around the globe in search of a 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 expanse,busily maintaining an artificially-cooled space inside an artificially一heated house一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 a food cabinet and turn off your fridge next winter. You may miss the hamburgers but at least you'll get ride of that terrible hum. Paragraph 4_______
[多选题]共用题干 Black Holes1 Black holes can be best described as a sort of vacuum,sucking up everything in space.Scientists have discovered that black holes come from an explosion of huge stars.Stars that are near death can no longer burn due to loss of fuel , and because its temperature can no longer control the gravitational(重力的)force,hydrogen ends up putting pressure onto the star's surface until it suddenly explodes then collapses.2 Black holes come from stars ihat are made of hydrogen,other gases and a few metals.When these explode it can turn into a stellar-mass(恒星质量) black hole , which can only occur if the star is large enough (should be bigger than the sun)for the explosion to break it into pieces,and the gravity starts to compact every piece into the tiniest particle.Try to see and compare:if a star that's ten times the size of the sun ends up being a black hole that's no longer than 70 kilometers,then the Earth would become a black hole that'S only a fraction of an inch!3 Objects that get sucked in a black hole will always remain there,never to break free.i1it remember that black holes can only gobble up(吞噬)objects within a specific distance to it.It's possible for a large star near the sun to become a black hole,but the sun will continue to stay in place.Orbits(轨道)do not change because the newly formed black hole contains exactly the same amount of mass as when it was a star, only this time its mass is totally contracted that it can end up as no bigger than a state.4 Sofar,astronomers have figured out that black holes exist because of Albert Einstcin's theory of relativity.In the end,through numerous studies,they have discovered that black holes truly exist.Since black holes trap light and do not give off light,it is nearly impossible to detect black holes via a telescope.But astronomers continue to study galaxies(银河系), space and the solar system to understand how black holes might evolve.It is possible that black holes can exist for millions of years,and later contribute to a bigger process in galaxies,which can eventually lead to creation of new entities(实体).Scientists also credit black holes as helpful in learning how galaxies began to form.
[多选题]共用题干 Climate Change:The Long Reach1.Earth is warming.Sea levels are rising.There's more carbon in the air,and Arctic ice is melting faster than at any time in recorded history.Scientists who study the environment to better gauge(评估) Earth's future climate now argue that these changes may not reverse for a very long time.2.People burn fossil fuels like coal and oil for energy.That burning releases carbon dioxide,a colorless gas.In the air,this gas traps heat at Earth's surface.And the more carbon dioxide released,the more the planet warms.If current consumption of fossil fuels doesn't slow,the long-term climate impacts could last thousands of years-and be more severe than scientists had been expecting.Climatologist RichardZeebe of the University of Hawaii at Manoa offers this conclusion in a new paper.3.Most climate-change studies look at what's going to happen in the next century or so.During that time, changes in the planet' s environment could nudge(推动)global warming even higher.For example, snow and ice reflect sunlight back into space.But as these melt,sunlight can now reach-and warm-the exposed ground.This extra heat raises the air temperature even more,causing even more snow to melt.This type of rapid exaggeration of impacts is called a"fast feedback".4.Zeebe says it's important to look at fast feedbacks.However,he adds,they're limited.From a climate change perspective,"This century is the most important time for the next few generations,"he told Science News."But the world is not ending in 2100."For this new study,Zeebe now focuses on"slow feedbacks".While fast feedback events unfold over decades or centuries,slow feedbacks can take thousands of years.Melting of continental ice sheets and the migration of plant life-as they relocate to more comfortable areas-are two examples of slow feedbacks.5.Zeebe gathered information from previously published studies investigating how such processes played out over thousands of years during past dramatic changes in climate.Then he came up with a forecast for the future that accounts for both slow and fast feedback processes.Climate forecasts that use only fast feedbacks predict a 4.5 degree Celsius(8.1 degree Fahrenheit)change by the year 3000.But slow feedbacks added another 1.5℃-for a 6℃ total increase,Zeebe reports.He also found that slow feedback events will cause global warming to persist for thousands of years after people run out of fossil fuels to burn. Paragraph 4______
[多选题]共用题干 Computer MouseThe basic computer mouse is an 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 on the page with the newer mice with the wheel. Most of us use the computer mouse daily without stopping to think how it works until it gets dirty and we have to learn how to clean it. We learn to point at thing before we learn to speak,so the mouse is a very natural pointing device.Other computer pointing devices include light pens,graphics tablets and touch screen,but the mouse is still our workhorse.The computer mouse was invented in 1964 by Douglas Englehart of Stanford University.As computer screens became popular and arrow keys were used to more 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 for 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 mouse ball. As the mouse ball in the bottom of the mouse rolls over the mouse pad,it presses against and turns two shafts.The shafts are connected to wheels with several small holes in them. The wheels have a pair of small electronic light-emitting devices called light emitting diodes (LED)mounted on either side.One LED sends a light beam to the LED on the other 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 later the light beam is blocked until the next hole is in place.The LED detects a changing pattern of light,converts the pattern into an electronic signal,and sends the signal to the computer through wires in a cable that goes out 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 screen.So far we have only discussed the basic computer mouse that most 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 the dirt. Eventually you have to clean your mouse. The newer optical mice avoid this problem by having no moving parts. The computer mouse derives its name from the cable that goes out its body,which looks like the tail of a mouse.
[多选题]共用题干 Toads are Arthritic and in PainArthritis(关节炎)is an illness that can cause pain and swelling in your bones. Toads(蟾蜍),a big problem 'in the north of Australia,are suffering from painful arthritis in their legs and backbone,a new stu街has shown. The toads that jump the fastest are more likely to be larger and to have longer legs.______(46)The large yellow toads,native to South and Central America,were introduced into the north-eastern Aus- tralian state of Queensland in 1935 in an attempt to stop beetles and other insects from destroying sugarcane crops.Now up to 200 million of the poisonous toads exist in the country,and they are rapidly spreading through the state of Northern Territory at a rate of up to 60 km a year. The toads can now be found across more than one million square kilometres.________(47)A Venezuelan poison virus was tried in the 1990s but had to be abandoned after it was found to also kill native frog species.The toads have severely affected ecosystems in Australia. Ariinials,arid sometimes pets,that eat the toads die im- mediately from their poison,and the toads themselves eat anything they can fit inside their mouth._________(48)A co-author of the new study,Rick Shine,a professor at the University of Sydney,says that little atten- tion has been given to the problems that toads face.Rick and his colleagues studied nearly 500 toads from Queensland and the Northern Territory and found that those in the latter state were very different.They were active,sprinting down roads and breeding quickly.According to the results of the study,the fastest toads travel nearly one kilometre a night._________(49) But speed and strength come at a price一arthritis of the legs and backbone due to constant pressure placed on them.In laboratory tests,the researchers found that after about 15 minutes of hopping,arthritic toads wouldtravel less distance with each hop(跳跃).________(50)These toads are so programmed to move, apparently,that even when in pain the toads travelled as fast and as far as the healthy ones,continuing their constant march across the landscape. __________(47)
[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 with-out 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 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,as,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 carried.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. Only when goods can be carried to all parts of the world quickly_______.
[多选题]共用题干 第三篇Hurricane(飓风)KatrinaA hurricane is a fiercely powerful , rotating(旋转的)form of tropical storm that can be 124 to 1,240 miles in diameter. The term hurricane is derived from Hurican,the name of a native American storm god.Hurricanes are typical of a calm central region of low pressure between 12 to 60 miles in diameter,known as the eye.They occur in tropical regions.Over its lifetime,one of these can release as much energy as 10,000 nuclear bombs.The seed for hurricane formation is a cluster(聚集)of thunderstorm over warm tropical waters. Hurricanes can only form and be fed when the sea一surface temperature exceeds 27℃and the surrounding atmosphere is calm. These requirements are met between June and November in the northern part of the world.Under these conditions, large quantities of water evaporate (蒸发)and condense(冷凝)into clouds and rain一releasing heat in the process.It is this heat energy,combined with the rotation of the Earth,that drives a hurricane.When the warm column of air from the sea surface first begins to rise,it causes an area of low pressure.This in turn creates wind as air is drawn into the area. This spinning wind drags up more moist air from the sea surface in a process that strengthens the storm. Cold air falls back to the ocean surface through the eye and on the outside of the storm.Initially,when wind speeds reach 23 miles per hour,these mild,wet and grey weather systems are known as depressions,or low air pressure.Hurricane Katrina formed in this way over the south-eastern Bahamas on 23 August 2005.Katrina has had a devastating impact on the Gulf Coast of the U.S.,leaving a disaster zone of 90,000 square miles in its wake(尾迹)—almost the size of the U.K.Thousands have been killed or injured and more than half a million people have become homeless in a humanitarian(人道主义的)crisis of a scale not seen in the U. S. since the Great Depression.The cost of the damage may top$100 billion. Which of the following is NOT true of Hurricane Katrina according to the last paragraph?
[多选题]共用题干 Face Masks May Not Protect from Super-Fluif a super-flu strikes,face masks may not protect you.Whether widespread use of masks will help,or harm during the next worldwide flu outbreak is a question that researchers are studying furiously.No results have come from their mask research yet. However,the government says peo-ple should consider wearing them certain situations anyway,just in case.But it's a question the public keeps asking while the government is making preparations for the next flu pandemic(大流行).So the Centers for Disease Control and Prevention(CDC)came up with preliminary guidelines."We don't want people wearing them everywhere,"said the CDC."The overall recommendation really is to avoid exposure."When that is not possible,the guidelines say you should consider wearing a simple surgical mask if you are in one of the three following situations. First,you're healthy and can't avoid going to a crowded place. Second,you're sick and think you may have close contact with the healthy, such as a family member checking on you .Third,you live with someone who's sick and thus might be in the early stages of infection,but still need to go out.Influenza pandemics can strike when the easy-to-mutate(变异)flu virus shifts to a strain(菌株)that people never have experienced.Scientists cannot predict when the next pandemic will ar- rive,although concern is rising that the Asian bird flu might trigger one if it starts spreading easily from person to person.During the flu pandemic,you should protect yourself. Avoid crowds,and avoid close contact with the sick unless you must care for someone.Why aren't masks added to this self-protection list?Because they can help trap virus-laden droplets flying through the air with a cough or sneeze. Simple surgical masks only filter the larger droplets.Besides,the CDC is afraid masks may create a false sense of security.Perhaps someone who should have stayed home would don(戴)an ill-fit-ting mask and hop on the subway instead.Nor does flu only spread through the air. Say someone covers a sneeze with his or her hand, then touches a doorknob or subway pole. if you touch that spot next and then put germy hands on your nose or mouth,you've been exposed. It's harder to rub your nose while wearing a mask,so your face may get pretty sweaty under masks. You reach under to wipe that sweat,and may transfer germs caught on the outside of the mask straight to the nose.These are the problems face masks may create for their users.Whether people should or should not use face masks still remains a question. The general public has to wait patiently for the results of the mask research scientists are still doing. What is the passage mainly about?
[多选题]共用题干 第三篇On the Trial of the Honey BadgerOn a recent field trip to the Kalahari Desert,a team of researchers learnt a lot more about honey badgers(灌).The team employed a local wildlife expert,Kitso Khama,to help them locate and follow thebadgers across the desert. Their main aim was to study the badgers'movements and behaviour as discreetly (谨慎地)as possible,without frightening them away or causing them to change their natural behaviour. They also planned to trap a few and study them close up before releasing them.In view of the animal's reputation, this was something that even Khama was reluctant to do."The problem with honey badgers is that they are naturally curious animals,especially when they see something new,"he says."That,combined with their unpredictable nature,can be a dangerous mixture.If they sense you have food,for example,they won't be shy about coming right up to you for something to eat. They're actually quite sociable creatures around humans,but as soon as they feel they might be in danger, they can become extremely vicious(凶恶的). Fortunately this is rare , but it does happen."The research confirmed many things that were already known.As expected,honey badgers ate any crea-tures they could catch and kill.Even poisonous snakes,feared and avoided by most other animals,were notsafe from them.The researchers were surprised,however,by the animal's fondness for local melons,probably because of their high water content. Previously researchers thought that the animal got all of its liquid require- ments from its prey(猎物).The team also learnt that,contrary to previous research findings,the badgers oc- casionally formed loose family groups.They were also able to confirm certain results from previous research, including the fact that female badgers never socialised with each other.Following some of the male badgers was a challenge,since they can cover large distances in a short space of time.Some hunting territories cover more than 500 square kilometers.Although they seem happy to share these territories with other males,there are occasional fights over an important food source,and male badgers can be as aggressive towards each other as they are towards other species.As the badgers became accustomed to the presence of people,it gave the team the chance to get up closeto them without being the subject of the animals'curiosity一or their sudden aggression.The badgers'eating patterns,which had been disrupted,returned to normal.It also allowed the team to observe more closely some of the other creatures that form working associations with the honey badger,as these seemed to adopt the badgers'relaxed attitude when near humans. What did the team find out about honey badgers?
[多选题]共用题干 First Image-recognition Software1. Dartmouth researchers and their colleagues have created an artificial intelligence software that uses photos to locate documents on the Internet with far greater accuracy than ever before.2. The new system,which was tested on photos and is now being applied to videos,shows for the first time that a machine learning algorithm(运算法则)for image recognition and retrieval is accurate and efficient enough to improve large-scale document searches online. The system uses pixel(像素)data in images and potentially video-rather than just text-to locate documents. It learns to recognize the pixels associated with a search phrase by studying the results from text-based image search en-gines. The knowledge gleaned(收集)from those results can then be applied to other photos without tags or captions(图片说明),making for more accurate document search results.3. "Over the last 30 years,"says Associate Professor Lorenzo Torresani,a co-author of the stud-y,"the Web has evolved from a small collection of mostly text documents to a modern,massive, fast-growing multimedia data set,where nearly every page includes multiple pictures or videos. When a person looks at a Web page, he immediately gets the gist(主旨)of it by looking at the pictures in it.Yet,surprisingly,all existing popular search engines,such as Google or Bing, strip away the information contained in the photos and use exclusively the text of Web pages to perform the document retrieval. Our study is the first to show that modern machine vision systems are accurate and efficient enough to make effective use of the information contained in image pix- els to improve document search."4. The researchers designed and tested a machine vision system-a type of artificial intelligence that allows computers to learn without being explicitly programmed-that extracts semantic(语义的)information from the pixels of photos in Web pages. This information is used to enrich the description of the HTML page used by search engines for document retrieval.The researchers test-ed their approach using more than 600 search queries(查询)on a database of 50 million Web pages. They selected the text-retrieval search engine with the best performance and modified it to make use of the additional semantic information extracted by their method from the pictures of the Web pages.They found that this produced a 30 percent improvement in precision over the original search engine purely based on text. The new system is expected to improve precision in______.
[多选题]共用题干 The Cold PlacesThe Arctic is a polar region.It surrounds the North Pole.Like Antarctica,the Arctic is a land of ice and snow.Antarctica holds the record for a low temperature reading-125 degrees Fahrenheit below zero. Reading of 85 degrees below zero is common in both the Arctic and Antarctica.Winter temperatures average 30 degrees below zero in the Arctic .At the South Pole the winter average is about 73 degrees below zero.One thing alone makes it almost impossible for men to live in Antarctica and in parts of the Arctic .This one thing is the low temperature-the killing chill of far North and the polar South.To survive,men must wear the warmest possible clothing. They must build windproof shelters .They must keep heaters going at all times.Not ever for a moment can they be unprotected against the below-zero temperatures.Men have a way of providing for themselves.Polar explorers wrap themselves in warm coats and furs .The cold makes life difficult. But the explorers can stay alive.What about animals?Can they survive?Do we find plants?Do we find life in the Arctic and in Antarctica?Yes,we do. There is life in the oceans.There is life on land.Antarctica,as we have seen,is a cold place indeed.But this has not always been the case.Expedition scientists have discovered that Antarctica has not always been a frozen continent. At one time the weather in Antarctica may have much like our own.Explorers have discovered coal in Antarctica. This leads them to believe that Antarctica at one time was a land of swamps and forests.Heat and moisture must have kept the trees in the forests alive.
[多选题]共用题干 Study Helps Predict Big Mediterranean Quake1.Scientists have found evidence that an overlooked fault in the eastern Mediterranean is likely to produce an earthquake and tsunami every 800 years as powerful as the one that destroyed Alexandria in AD 365.2.Using radiocarbon dating techniques,simulations and computer models,the researchers recreated the ancient disaster in order to identify the responsible fault."We are saying there is probably a repeat time of 800 years for this kind of earthquake,"said Ms Beth Shaw,an earthquake scientist at the University of Cambridge,who led the study. Scientists study past earthquakes in order to deter-mine the future possibility of similar large shocks.3.Identifying the fault for the AD 365 earthquake and tsunami is important for the tens of millions of people in the region,Ms.Shaw said.The fault close to the southwest coast of Crete last produced a big enough quake to generate a tsunami about 1300,which means the next powerful one could come in the next 100 years,she added in a telephone interview.4.Ms.Shaw and her colleagues calculate the likely intervals by measuring the motion of either side of the fault to find how often such large earthquakes would have to occur to account for that level of motion,she said.Their computer model suggested an 8 magnitude quake on the fault would pro-duce a tsunami that floods the coastal regions of Alexandria and North Africa,the southern coast of Greece and Sicily all the way up the Adriati to Dubrovnik.This would be similar to the ancient quake in AD 365 that caused widespread destruction in much of Greece and unleashed a tsunami that flooded Alexandria and the Nile Delta likely killing tens of thousands of people,she said. The earthquake prediction devices developed by Ms.Shaw are being widely used in the world.
[多选题]共用题干 Europa's Watery UnderworldEuropa,one of Jupiter's 63 known moons,looks bright and icy on the surface.But appearances can be deceiving:Miles within its cracked,frigid shell,Europa probably hides giant pools of liquid water. Where scientists find liquid water,they hope to find life as well.Since we can't go diving into Europa's depths just yet,scientists instead have to investigate the moon's surface for clues to what lies beneath.In a new study,scientists investigated one group of strange ice patterns on Europa and concluded that the formations mark the top of an underground pool that holds as much water as the U.S.Great Lakes.Pictures of Europa,which is slightly smaller than Earth's moon,clearly show a tangled,icy mishmash of lines and cracks known as"chaos terrains".These chaotic places cover more than half of Europa. For more than 10 years,scientists have wondered what causes the formations.The new study suggests that they arise from the mixing of vast underground stores of liquid water with icy material near the surface.For scientists who suspect that Europa also may be hiding life beneath its icy surface,the news about the new lake is exciting."It would be great if these lakes harbored life,"Britney Schmidt,a planetary scientist who worked onthe study,told Science News."But even if they didn't,they say that Europa is doing something interesting and active right now."Schmidt,a scientist at the University of Texas at Austin,and her colleagues wanted to know how chaos terrains form.Since they couldn't rocket to Europa to see for themselves,they searched for similar forma- tions here on Earth.They studied collapsed ice shelves in Antarctica and icy caps on volcanoes in Iceland. Those features on Earth formed when liquid water mixed with ice.The scientists now suspect something similar might be happening on Europa:that as water and ice of different temperatures mingle and shift,the surface fractures.This would explain the jumbled ice sculptures."Fracturing catastrophically disrupts the ice in the same way that it causes ice shelves to collapse on Earth,"Schmidt told Science News.She and her team found that the process could be causing chaos terrains to form quickly on Europa.The new study suggests that on this moon,elements such as oxygen from the surface blend with the deep bodies of water. That mixture may create an environment that supports life. The size of Europa is a bit larger than that of Earth's moon.
[多选题]共用题干 第三篇The Age of being Bullied and Its EffectThe age at which kids first fall victim to bullying(欺辱)could influence how strongly they are affected,suggests a new study.And,surprisingly,it is not the youngest kids who are hurt the most in the long term. Bullying can have long-lasting effects,but particularly when it begins in adolescence(青春期),the researchers say.People subjected to either oral or physical bullying are known to be at greater risk for developing depression,anxiety disorders or to behave violently.But not everyone reacts in this way.Children bullied for the first time before their adolescence seem to get over it,but those who are victimized for the first time late on in adolescence seem to become more aggressive or are more likely to turn to drink as a means of coping. These are the conclusions of psychologist Matthew Newman and his colleagues from the University of Texas at Austin,U.S.The team gave questionnaires to nearly 1,500 college students regarding their experience of physical and psychological bullying before adolescence一before high school一and in late adolescence一at high school.They assessed mood and mental state,judging by signs of anxiety or depression,such as sleeplessness.The group was also questioned about how they would react to certain challenges,such as being embarrassed or provoked.People who were bullied all revealed slightly higher levels of stress.But while those bullied earlier in life seemed to respond normally to provocation,people bullied for the first time late in adolescence are more withdrawn and sensitive to violence.The best solution was strong social support,whether from friends,family or school.Those with no one to share their problems were suffered the most.So perhaps it is best not to shelter children completely from bullying early on,suggests Newman."They may get stressed,but unhealthy coping really jumps out when they are bullied for the first time later on."The effects are likely to be related to the developing stress hormone system, which matures during adolescence,he concludes.Studies show abnormal stress responses in adult animals that experience social stress or aggression from other animals during adolescence.
[多选题]共用题干 Thirst for OilWorldwide every day,we devour the energy equivalent of about 200 million barrels of oil.Most of the energy on Earth comes from the Sun.In fact enough energy from the Sun hits the planet's surface each minute to cover our needs for an entire year,we just need to find an efficient way to use it. So far the energy in oil has been cheaper and easier to get at. But as supplies dwindle,this will change,and we will need to cure our addiction to oil.Burning wood satisfied most energy needs until the steam-driven industrial revolution,when energy-dense coal became the fuel of choice.Coal is still used,mostly in power stations,to cover one quarter of our energy needs,but its use has been declining since we started pumping up oil.Coal is the least efficient,unhealthiest and most environmentally damaging fossil fuel,but could make a comeback,as supplies are still plentiful:its reserves are five times larger than oil's.Today petroleum,a mineral oil obtained from below the surface of the Earth and used to pro- duce petrol,diesel oil and various other chemical substances,provides around 40% of the world's energy needs,mostly fuelling automobiles.The US consumes a quarter of all oil,and generates a similar proportion of greenhouse gas emissions.The majority of oil comes from the Middle East,which has half of known reserves.But other significant sources include Russia,North America,Norway,Venezuela and the North Sea.Alaska's Arctic National Wildlife Refuge could be a major new US source,to reduce reliance on foreign imports.Most experts predict we will exhaust easily accessible reserves within 50 years,though opinions and estimates vary.We could fast reach an energy crisis in the next few decades,when demand exceeds supply.As conventional reserves become more difficult to access,others such as oil shales and tar sands may be used instead.Petrol could also be obtained from coal.Since we started using fossil fuels,we have released 400 billion tonnes of carbon,and burn- ing the entire reserves could eventually raise world temperatures by 13℃.Among other horrors, this would result in the destruction of all rainforests and the melting of all Arctic ice. Which of the following statements is NOT meant by the author,according to the second paragraph?
[多选题]共用题干 The Interpersonal Skills of Children without SiblingsMany parents may think that each new sibling(兄弟姐妹)offers their children the gift of companionship.But while we tend to think that siblings teach one another conflict resolution and other 、interpersonal skills,new research says they are no better off socially than children without siblings."Most studies look at the negative consequences of having siblings in terms of educational outcome,"said Donna Bobbitt-Zeher,lead author of Good for Nothing?Number of Siblings and Friendship Nominations Among Adolescents."But we decided to look at social skills to see if there was any other possible benefit to having brothers or sisters."She and her co-author,Douglas Downey are sociologists at Ohio State's Marion campus,and neither is an only child.They presented their findings at the annual meeting of the American Sociological Association in August.The paper is in large part a reply to a previous study,Playing Well With Others in Kindergarten:The Benefits of Siblings at Home,also co-authored by Dr. Downey,which found that kindergarten teachers rated children without siblings worse in interpersonal skills,self-control and problem behaviors.But an only child isn't necessarily a loner and misfit.First,the social advantages found in children with siblings in the kindergarten study were quite modest. Second,the study relied on teacher evaluations,and teachers may not be reliable judges of friendships among their charges.And now it seems that any benefits documented in kindergarten disappear altogether by middle school. Using a metric called"peer nomination(提名)",Dr. Downey and Dr. Bobbitt Zeher found that children without siblings had just as many friends as children with siblings."I see the two studies as a natural progression,showing what happens to the only children who didn't have much interaction before kindergarten,"Dr. Downey said.Another study he is working on shows that the same only children evaluated in kindergarten had caught up by fifth grade.While the studies don't examine the cause for the disappearing social boost to kindergartners with siblings,Dr. Downey speculates that continuing school,youth clubs and other group activities一especially in an era of overscheduled children一provide sufficient opportunity for onlys to sharpen their skills. Donna Bobbitt Zeher's study is to find out if having siblings is_______.
[多选题]共用题干 InflationBusiness and government leaders also consider the inflation rate to be an important general indicator. Inflation is a period of increased spending that causes rapid rises in prices._______(51)your money buys fewer goods so that you get_______(52)for the same amount of money as before,inflation is the problem. There is a general rise_______(53)the price of goods and services.Your money buys less.Sometimes people describe inflation as a time when"a dollar is not worth a dollar anymore".Inflation is a problem for all consumers.People who live on a fixed income are hurt the _______(54).Retired people,for instance,cannot count on an increase in income as prices rise. Elderly people who do not work face serious problems in stretching their incomes to_______(55) their needs in time of inflation.Retirement income_______(56)any fixed income usually does not rise as fast as prices.Many retired people must cut their spending to_______(57)rising prices.In many cases they must stop_______(58)some necessary items,such as food and clothing. Even _______(59)working people whose incomes are going up,inflation can be a problem. The_______(60)of living goes up,too. People who work must have even more money to keep up their standard of living. Just buying the things they need costs more.When incomes do not keep _______(61)with rising prices,the standard of living goes down.People may be earning the same amount of money,but they are not living as well because they are not able to buy as many goods and services.Government units gather information about prices in our economy and publish it as price indexes _______(62)the rate of change can be determined.A price index measures changes in prices using the price for a_______(63)year as the base.The base price is set at 100,and the other prices are reported as a_______(64)of the base price.A price index makes_______(65)possible to compare current prices of typical consumer goods,for example,with prices of the same goods in previous years. _________(61)
[多选题]共用题干 The Differences Among Various Types of AdoptionIn the US,there is a difference between public and private adoption.Public adoption typically involves taking _________ (51) foster(收养的)children and then adopting them after several months.It's significantly less expensive than private or international adoption,but more often than not_______(52)adopting children who are older than 5 or who have_______(53)needs.Private adoptions offer a better chance of adopting newborns,and increasingly,birth parents _______(54)the adoptive parents themselves.That's not a bad idea on its face,as it gives biological parents_______ (55)say in whom they will relinquish(放弃)their children. But this effectively puts_______(56)parents in the position of advertising themselves to birth parents in newspapers and online,_______(57)many couples feel uncomfortable with.Most states allow birth parents to reclaim their children_______(58)the children have been placed with adoptive families,for time periods ranging from a few days in some states to several months in others.Critics of international adoption say this rarely happens.They are only_______ (59)right:it's true that American birth parents don't usually reclaim their children once they've been placed with their adoptive families,but they can and do_______(60)their minds before the papers are signed.International adoption is more expensive than any form of domestic adoption,but in many ways, it is also more straightforward.The_______(61)of a birth parent calling the adoption_______ (62)are effectively zero and while costs are high,they're also determined at the_______(63) and tend not to change as the_______(64)wears on.Couples seeking to adopt should consider all_______(65)and get a range of perspectives before deciding which method is best for them. _________(62)
[多选题]共用题干 New Understanding of Natural Silk's MysteriesNatural silk,as we all know,has a strength that man-made materials have long struggled to match.In a discovery that sounds more like an ancient Chinese proverb than a materials science breakthrough,MIT re- searchers have discovered that silk gets its strength from its weakness.Or,more specifically,its many weak- nesses. Silk gets its extraordinary durability and ductility(柔韧性)from an unusual arrangement of hydrogen bonds that are intrinsically very weak but that work together to create a strong,flexible structure.Most materials一especially the ones we engineer for strength一get their toughness from brittleness.As such,natural silks like those produced by spiders have long fascinated both biologists and engineers because of their light weight,ductility and high strength(pound for pound,silk is stronger than steel and far less brittle). But on its face,it doesn't seem that silks should be as strong as they are;molecularly,they are held together by hydrogen bonds , which are far weaker than the covalent(共价的)bonds found in other molecules.To get a better understanding of how silk manages to produce such strength through such weak bonds, the MIT team created a set of computer models that allowed them to observe the way silk behaves at the atomic level. They found that the arrangement of the tiny silk nanocrystals(纳米晶体)is such that the hydro- gen bonds are able to work cooperatively,reinforcing one another against external forces and failing slowlywhen they do fail,so as not to allow a sudden fracture to spread across a silk structure.The result is natural silks that can stretch and bend while retaining a high degree of strength.But while that's all well and good for spiders,bees and the like,this understanding of silk geometry could lead to new materials that are stronger and more ductile than those we can currently manufacture.Our best and strongest materials are generally expensive and difficult to produce(requiring high temperature treatments or energy-intensive processes).By looking to silk as a model,researchers could potentially devise new manufacturing methods that rely on inexpensive materials and weak bonds to create less rigid,more forgiving materials that are nonetheless stronger than anything currently on offer. And if you thought you were going to get out of this materials science story without hearing about carbon nanotubes(纳米碳管), think again. The MIT team is already in the lab looking into ways of synthesizing silk-like structures out of materials that are stronger than natural silk-like carbon nanotubes. Super-silks are on the horizon. Biologists and engineers are interested in understanding natural silks because they are very light and brittle.
[多选题]共用题干 Young Adults Who Exercise Get Higher IQ ScoresYoung adults who are fit have a higher IQ and are more likely to go on to university,reveals a major new study_________(51)out at the Sahlgrenska Academy and Sahlgrenska University Hospital.The results were recently published in the Proceedings of the National Academy of Sciences(PNAS).The study__________(52)1._________(1.)2 million Swedish men doing military service who were born between 1950 and1976._________(1976.)The research group analyzed the ________(53)of both physical and IQ tests the youngsters took right after they started serving the army.The study shows a clear link _________(54)good physical fitness and better results for the IQ test.The strongest links are for ________(55)thinking and verbal comprehension.But it is only fitness thatplays a _________ (56)in the results for the IQ test,and not strength."Being fit means that you also havegood heart and lung __________(57)and that your brain gets plenty of oxygen."says Michael Nilsson,pro-fessor at the Sahlgrenska Academy and chief physician at the Sahlgrenska University Hospital."This may be one of the reasons why we can see a clear link with fitness,but not with muscular_________(58).We are also seeing that there are growth factors that are important."By analyzing data for twins,the researchers have been________(59)to determine that it is primarily environmental factors and not genes that___________(60)the link between fitness and a higher IQ."We have also shown that those youngsters who _______(61)their physical fitness between the ages of 1 5 and 1 8 increase their performance."says Maria Aberg,researcher at the Sahlgrenska Academy andphysician at Aby health centre."This being the case,physical education is a_______(62)that has an important place in schools,and is an absolute must________(63)we want to do well in math and other theoretical subjects."The researchers have also compared the results from fitness tests during national service_______(64) the socioeconomic status of the men later in life.Those who were fit at I 8 were more__________(65)to go into higher education,and many secured more qualified jobs. _________(51)
[多选题]共用题干 InflationBusiness and government leaders also consider the inflation rate to be an important general indicator. Inflation is a period of increased spending that causes rapid rises in prices._______(51)your money buys fewer goods so that you get_______(52)for the same amount of money as before,inflation is the problem. There is a general rise_______(53)the price of goods and services.Your money buys less.Sometimes people describe inflation as a time when"a dollar is not worth a dollar anymore".Inflation is a problem for all consumers.People who live on a fixed income are hurt the _______(54).Retired people,for instance,cannot count on an increase in income as prices rise. Elderly people who do not work face serious problems in stretching their incomes to_______(55) their needs in time of inflation.Retirement income_______(56)any fixed income usually does not rise as fast as prices.Many retired people must cut their spending to_______(57)rising prices.In many cases they must stop_______(58)some necessary items,such as food and clothing. Even _______(59)working people whose incomes are going up,inflation can be a problem. The_______(60)of living goes up,too. People who work must have even more money to keep up their standard of living. Just buying the things they need costs more.When incomes do not keep _______(61)with rising prices,the standard of living goes down.People may be earning the same amount of money,but they are not living as well because they are not able to buy as many goods and services.Government units gather information about prices in our economy and publish it as price indexes _______(62)the rate of change can be determined.A price index measures changes in prices using the price for a_______(63)year as the base.The base price is set at 100,and the other prices are reported as a_______(64)of the base price.A price index makes_______(65)possible to compare current prices of typical consumer goods,for example,with prices of the same goods in previous years. _________(52)
[多选题]共用题干 第二篇Download Knowledge Directly to Your BrainFor the first time,researchers have been able to hack into the process of learning in the biain,using induced brain patterns to create a learned behavior. It's not quite as advanced as an instant Kung-fu down- load,and it's not as sleek as cognitive inception,but it's still an important finding that could lead to new teaching and rehabilitation techniques.Future therapies could decode the brain activity patterns of an athlete or a musician,and use them as a benchmark for teaching another person a new activity,according to the researchers.Scientists from Boston University and ATR Computational Neuroscience Laboratories in Kyoto used functional magnetic resonance imaging,or fMRI,to study the learning process.They were examining the adult brain's aptitude for visual perceptual learning,or VPL,in which repetitive training improves a per- son's performance on a particular task.Whether adults can do this as well as young people has been an on- going debate in neuroscience.Led by BU neuroscientist Takeo Watanabe,researchers used a method called decoded fMRI neurofeed- back to stimulate the visual cortex.First they showed participants circles at different orientations.Then they used fMRI to watch the participants'brain activity.The researchers were then able to train the participants to recreate this visual cortex activity.The volunteers were again placed in MRI machines and asked to visualize shapes of certain colors.The participants were asked to"somehow regulate activity in the posterior part of the brain"to make a solid green disc as large as they could.They were told they would get a paid bonus proportional to the size of this disc, but they weren't told anything about what the disc meant.The researchers watched the participants'brain activity and monitored the activation patterns in their visual cortices."Participants can be trained to control the overall mean activation of an entire brain region,"the study authors write,"or the adtivation in one region relative to that in another region."This worked even when test subjects were not aware of what they were learning,the researchers said."The most surprising thing in this study is that mere inductions of neural activation patterns corresponding to a specific visual feature led to visual performance improvement on the visual feature,without presenting the fea- ture or subjects' awareness of what was to be learned,"Watanabe said in a statement.Watanabe and colleagues said this method can be a powerful tool."It can'incept' a person to acquire new learning, skills,or memory,or possibly to restore skills or knowledge that has been damaged through accident,disease,or aging,without a person's awareness of what is learned or memorized,"they write. Which of the following statements is true of the experiment participants?
[多选题]共用题干 InflationBusiness and government leaders also consider the inflation rate to be an important general indicator. Inflation is a period of increased spending that causes rapid rises in prices._______(51)your money buys fewer goods so that you get_______(52)for the same amount of money as before,inflation is the problem. There is a general rise_______(53)the price of goods and services.Your money buys less.Sometimes people describe inflation as a time when"a dollar is not worth a dollar anymore".Inflation is a problem for all consumers.People who live on a fixed income are hurt the _______(54).Retired people,for instance,cannot count on an increase in income as prices rise. Elderly people who do not work face serious problems in stretching their incomes to_______(55) their needs in time of inflation.Retirement income_______(56)any fixed income usually does not rise as fast as prices.Many retired people must cut their spending to_______(57)rising prices.In many cases they must stop_______(58)some necessary items,such as food and clothing. Even _______(59)working people whose incomes are going up,inflation can be a problem. The_______(60)of living goes up,too. People who work must have even more money to keep up their standard of living. Just buying the things they need costs more.When incomes do not keep _______(61)with rising prices,the standard of living goes down.People may be earning the same amount of money,but they are not living as well because they are not able to buy as many goods and services.Government units gather information about prices in our economy and publish it as price indexes _______(62)the rate of change can be determined.A price index measures changes in prices using the price for a_______(63)year as the base.The base price is set at 100,and the other prices are reported as a_______(64)of the base price.A price index makes_______(65)possible to compare current prices of typical consumer goods,for example,with prices of the same goods in previous years. _________(64)
[多选题]共用题干 第一篇What's NASDAQ?NASDAQ is a familiar but strange name for people.We often learn its news via different kinds of media,though quite a lot of people can not tell what exactly it means.NASDAQ,short for the National Association of Securities Dealers Automated Quotations system,is one of the largest market in the world for stocks trading. The number of companies in NASDAQ is more than that of the other stock exchange in America,including the New York Stock Exchange(NYSE)and the American Stock Exchange(AMEX).Most of the companies listed on NASDAQ are smaller than most of those on the NYSE and AMEX.NASDAQ has become recognized as the home of new technology companies,especially computer and computer-related businesses.Trading on NASDAQ is initiated by stock brokers acting on behalf of their clients.The brokers negotiate with market makers who concentrate on trading specific stocks to reach a price for the stock.Different from other stock exchange,NASDAQ has no central location where trading takes place.Instead,its market makers can be found all over the country and make trades by telephone and via the Internet. Since brokers and market makers trade stocks directly instead of on the floor of a stock exchange,NASDAQ is called an over-the-counter market. The term over-the-counter refers to the direct nature of the trading,as in a store where goods are handed over a counter.Since its foundation in 1971,the NASDAQ Stock Market has been the innovator. As the world's first electronic stock market,NASDAQ long ago set a precedent for technological trading innovation that is unrivaled.Now poised to become the world's first truly global market,the NASDAQ Stock Market is the market of choice for business industry leaders worldwide.By providing an efficient environment for raising capital NASDAQ has helped thousands of companies achieve their desired growth and successfully make the leap into public ownership. What does the passage mainly tell us?
[多选题]共用题干 第一篇What's NASDAQ?NASDAQ is a familiar but strange name for people.We often learn its news via different kinds of media,though quite a lot of people can not tell what exactly it means.NASDAQ,short for the National Association of Securities Dealers Automated Quotations system,is one of the largest market in the world for stocks trading. The number of companies in NASDAQ is more than that of the other stock exchange in America,including the New York Stock Exchange(NYSE)and the American Stock Exchange(AMEX).Most of the companies listed on NASDAQ are smaller than most of those on the NYSE and AMEX.NASDAQ has become recognized as the home of new technology companies,especially computer and computer-related businesses.Trading on NASDAQ is initiated by stock brokers acting on behalf of their clients.The brokers negotiate with market makers who concentrate on trading specific stocks to reach a price for the stock.Different from other stock exchange,NASDAQ has no central location where trading takes place.Instead,its market makers can be found all over the country and make trades by telephone and via the Internet. Since brokers and market makers trade stocks directly instead of on the floor of a stock exchange,NASDAQ is called an over-the-counter market. The term over-the-counter refers to the direct nature of the trading,as in a store where goods are handed over a counter.Since its foundation in 1971,the NASDAQ Stock Market has been the innovator. As the world's first electronic stock market,NASDAQ long ago set a precedent for technological trading innovation that is unrivaled.Now poised to become the world's first truly global market,the NASDAQ Stock Market is the market of choice for business industry leaders worldwide.By providing an efficient environment for raising capital NASDAQ has helped thousands of companies achieve their desired growth and successfully make the leap into public ownership. What can be inferred from the passage?
[多选题]共用题干 The Differences Among Various Types of AdoptionIn the US,there is a difference between public and private adoption.Public adoption typically involves taking _________ (51) foster(收养的)children and then adopting them after several months.It's significantly less expensive than private or international adoption,but more often than not_______(52)adopting children who are older than 5 or who have_______(53)needs.Private adoptions offer a better chance of adopting newborns,and increasingly,birth parents _______(54)the adoptive parents themselves.That's not a bad idea on its face,as it gives biological parents_______ (55)say in whom they will relinquish(放弃)their children. But this effectively puts_______(56)parents in the position of advertising themselves to birth parents in newspapers and online,_______(57)many couples feel uncomfortable with.Most states allow birth parents to reclaim their children_______(58)the children have been placed with adoptive families,for time periods ranging from a few days in some states to several months in others.Critics of international adoption say this rarely happens.They are only_______ (59)right:it's true that American birth parents don't usually reclaim their children once they've been placed with their adoptive families,but they can and do_______(60)their minds before the papers are signed.International adoption is more expensive than any form of domestic adoption,but in many ways, it is also more straightforward.The_______(61)of a birth parent calling the adoption_______ (62)are effectively zero and while costs are high,they're also determined at the_______(63) and tend not to change as the_______(64)wears on.Couples seeking to adopt should consider all_______(65)and get a range of perspectives before deciding which method is best for them. _________(57)
[多选题]共用题干 The Differences Among Various Types of AdoptionIn the US,there is a difference between public and private adoption.Public adoption typically involves taking _________ (51) foster(收养的)children and then adopting them after several months.It's significantly less expensive than private or international adoption,but more often than not_______(52)adopting children who are older than 5 or who have_______(53)needs.Private adoptions offer a better chance of adopting newborns,and increasingly,birth parents _______(54)the adoptive parents themselves.That's not a bad idea on its face,as it gives biological parents_______ (55)say in whom they will relinquish(放弃)their children. But this effectively puts_______(56)parents in the position of advertising themselves to birth parents in newspapers and online,_______(57)many couples feel uncomfortable with.Most states allow birth parents to reclaim their children_______(58)the children have been placed with adoptive families,for time periods ranging from a few days in some states to several months in others.Critics of international adoption say this rarely happens.They are only_______ (59)right:it's true that American birth parents don't usually reclaim their children once they've been placed with their adoptive families,but they can and do_______(60)their minds before the papers are signed.International adoption is more expensive than any form of domestic adoption,but in many ways, it is also more straightforward.The_______(61)of a birth parent calling the adoption_______ (62)are effectively zero and while costs are high,they're also determined at the_______(63) and tend not to change as the_______(64)wears on.Couples seeking to adopt should consider all_______(65)and get a range of perspectives before deciding which method is best for them. _________(56)
[多选题]共用题干 Learn About Noble Gases(惰性气体)1 Have you ever ridden on a balloon?Many tourist spots offer balloon rides in order for people to see the beauty of a place from above.A balloon contains a noble gas called helium(氦).Formerly,balloons con- tamned hydrogen but hydrogen is very flammable and dangerous when uncontrolled.Therefore,people shiftedto helium,which is safer. Helium is safe because it has the properties of the noble gases.2 People once believed that noble gases couldn't chemically react at all.For this reason,they were called inert gases(隋性气体).They were also listed under Group 0 in the old periodic table because scien- tists believed that the gases have zero valence(价)electrons in their outer shell.This was later proven to be untrue when some noble gas compounds were discovered.3 The gases are elements,which share similar properties.These properties include being monoatomic, colorless,odorless,being able to conduct electricity,and having low chemical reactivity.Noble gases include helium,neon,argon,krypton,xenon and radon.These are all found in Group 18,in the right most column of the periodic table.If you look at the periodic table,you will notice that these elements are the only ones which do not have a charge. Helium has the lowest molecular(分子的)weight while radon is theheaviest.4 Remember that chemical reactions occur because atoms have valence electrons,which are electrons in their outer shell.When the outer shell is"unfilled"or the required number of electrons is not yet com- plete,the atom is more reactive.Noble gases have a full outer shell,meaning that they have complete elec- trons in their outer shell.This complete number varies.For instance,the outer shell of helium has 2 valence electrons while the outer shell of xenon has 8 electrons.Nowadays,there remains to be a few noble gases because of the low chemical reactivity of these said gases.5 because of their properties,noble gases have many important applications.They are widely used in medicine and industries. For instance , liquid helium is used for superconducting magnets(磁体).These magnets are very important in physics and medicine.When a doctor suspects that a person's brain has been damaged,he might request for Magnetic Resonance Imaging(MRI).MRI allows the doctor to"see"the brain,without operating on the patient. Paragraph 2________
[多选题]共用题干 第二篇Explorer of the Extreme DeepOceans cover more than two-thirds of our planet.Yet,just a small fraction of the underwater world has been explored.Now,Scientists at the Woods Hole Oceanographic Institution(WHOI)in Massachusetts are building an underwater vehicle that will carry explorers as deep as 6,500 meters (21,325.5 feet).The new machine,known as a manned submersible or human-operated vehicle (HOV),will replace another one named Alvin which has an amazing record of discovery,playing a key role in various important and famous undersea expeditions.Alvin has been operating for 40 years but can go down only 4,500 meters(14,763.8 feet).It's about time for an upgrade,WHOI researchers say.Alvin was launched in 1964.Since then,Alvin has worked between 200 and 250 days a year, says Daniel Fornari,a marine geologist and director of the Deep Ocean Exploration Institute at WHOI.During its lifetime,Alvin has carried some 12,000 people on a total of more than 3,000 dives.A newer,better versions of Alvin is bound to reveal even more surprises about a world that is still full of mysteries,Fornari says.It might also make the job of exploration a little easier."We take so much for granted on land."Fornari says."We can walk around and see with our eyes how big things are.We can see colors,special arrangements."Size-wise,the new HOV will be similar to Alvin.It'll be about 37 feet long. The setting area inside will be a small sphere,about 8 feet wide,like Alvin.It'll carry a pilot and two passengers.It will be just as maneuverable.In most other ways,it will give passengers more opportunities to enjoy the view,for one thing. Alvin has only three windows,the new vehicle will have five,with more overlap so that the passengers and the pilot can see the same thing.Alvin can go up and down at a rate of 30 meters every second,and its maximum speed is 2 knots(about 2.3 miles per hour),while the new vehicle will be able to ascend and descend at 44 meters per second.It'll reach speeds of 3 knots,or 3.5 miles per hour. Which of the following statements is NOT a fact about Alvin?
[多选题]共用题干 第二篇Some People do Not Taste Salt Like OthersLow-salt foods may be harder for some people to like than others,according to a study by a Penn State College of Agricultural Sciences food scientist.The research indicates that genetic factors influence some of the difference in the levels of salt we like to eat.Those conclusions are important because recent,well-publicized efforts to reduce the salt content in food have left many people struggling to accept fare that simply does not taste as good to them as it does to others, pointed out John Hayes,assistant professor of food science who was lead investigator on the study.Diets high in salt can increase the risk of high blood pressure and stroke.That is why public health ex- perts and food companies are working together on ways to help consumers lower salt intake through foods that are enjoyable to eat.This study increases undersfanding of salt preference and consumption.The research involved 87 carefully screened participants who sampled salty foods such as soup andchips,on multiple occasions,spread out over weeks.Test subjects were 45 men and 42 women,reportedly healthy,ranging in age from 20 to 40 years.The sample was composed of individuals who were not actively modifying their dietary intake and did not smoke cigarettes.They rated the intensity of taste on a commonly used scientific scale,ranging from barely detectable to strongest sensation of any kind."Most of us like the taste of salt.However,some individuals eat more salt,both because they like the taste of saltiness more,and also because it is needed to block other unpleasant tastes in food,"said Hayes. "Supertasters,people who experience tastes more intensely,consume more salt than nontasters do.Snack foods have saltiness as their primary flavor,and at least for these foods,more is better,so the supertasters seem to like them more."However,supertasters also need higher levels of salt to block unpleasant bitter tastes in food such as cheese,Hayes noted."For example,cheese is a wonderful blend of dairy flavors from fermented milk,but al- so bitter tastes from ripening that are blocked by salt,"he said."A supertaster finds low-salt cheese unpleasant because the bitterness is too pronounced."Hayes cited research done more than 75 years ago by a chemist named Fox and a geneticist named Blakeslee,showing that individuals differ in their ability to taste certain chemicals.As a result,Hayes ex- plained,we know that a wide range in taste acuity exists,and this variation is as normal as variations in eye and hair color."Some people,called supertasters,'describe bitter compounds as being extremely bitter,while others, called nontasters,find these same bitter compounds to be tasteless or only weakly bitter,"he said."Response to bitter compounds is one of many ways to identify biological differences in food preference because super- tasting is not limited to bitterness." It can be inferred from the last paragraph that taste acuity is_______.
[多选题]共用题干 The Fridge1.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一natural cooling,drying,smoking,slating, sugaring,bottling…4.What refrigeration did promote was marketing一marketing hardware and electricity,marketing soft drinks,marketing dead bodies of animals around the globe in search of a 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 expanse,busily maintaining an artificially-cooled space inside an artificially一heated house一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 a food cabinet and turn off your fridge next winter. You may miss the hamburgers but at least you'll get ride of that terrible hum. Paragraph 4_______
[多选题]共用题干 Science and Truth“FINAGLE”(欺骗)is not a word that most people associate with science. One reason is that the image of the scientist is of one who always______ (51)data in an impartial(不偏不倚的)search for truth. In any debate______ ( 52 ) intelligence , schooling , energy—the phrase“science says”usually disarms opposition.But scientists have long acknowledged the existence of a“finagle factor”—a tendency by many scientists to give a helpful change to the data to______(53)desired results.The latest of the finagle factor in action comes from Stephen Jay Gould,a Harvard biologist,who has ______(54)the important 19th century work of Dr. Samuel George Morton.Morton was fa-mous in his time for analysing the brain______(55)of the skulls as a measure of intelligence.He concluded that whites had the largest brains,that the brains of Indians and blacks were smaller,and______(56),that whites constitute a superior race.Gould went back to Morton's original data and concluded that the______(57)were an example of the finagle at work .He found that Morton's“discovery”was made by leaving out embarrassing data,______(58)incorrect procedures,and changing his criteria-again,always in fayour of his argument. Morton has been thoroughly discredited by now and scientists do not believe that brain size reflects______(59).But Gould went on to say Morton's story is only an example of a common problem in ______(60)work .Some of the leading figures in science are______(61)to have used the finagle factor. Gould says that Isaac Newton fudged out(捏造)to support at least three central statements that he could not prove .And so______(62)Laudius Ptolemy,the Greek astronomer,whose master work,Almagest,summed up the case for a solar system that had the earth asits centre .Recent______(63)indicate that Ptolemy either faked some key data or resorted heavily to the finagle factor.All this is important because the finagle factor is still at work.For example,in the artificial sweetener controversy,it is______(64)that all the studies sponsored by the sugar industry find that the artificial sweetener is unsafe,______(65)all the studies sponsored by the diet food industry find nothing wrong with it. 55._________
[多选题]共用题干 The Arctic Ice is ThawingFather Christmas may have to move his"workshop"from the North Pole because global warming is thawing the ice beneath his feet and his reindeers' feet as well.His"workshop"is in dire straits. The"platform"for the"workshop"is melting,said Stefan Norris of the World Wildlife Fund Environmental Group's Arctic Program.An eight-nation report by 250 scientists published recently predicted the Arctic Ocean could be ice-free in summer by 2100 because of a build-up of heat-trapping gases in the atmosphere,mainly from burning fossil fuels in cars or factories.The North Pole is getting more and more inhabitable to Father Christmas._______(46)Young people learn that,Father Christmas'"workshop"produces millions of gifts delivered by him on a flying,reindeer-drawn sleigh.Hollywood movies like The Polar Express tried to make viewers believe that Father Christmas lives at the North Pole._______(47)The"Fortress of Solitude"is near the North Pole that could be under threat in a warmer world.Ian Boldt,spokesman of the Danish Ministry of Science,suggested ways to rescue Father Christmas. _______(48)Another alternative,he argued,would be building some electrical facilities to ensure the ice stays on the North Pole for him."This should be a subject for the United Nations."he said. "Danmark could build windmills to provide Father Christmas with power."Denmark says Father Christmas's real home is Greenland,which will help,Denmark thinks,to strengthen its position in claiming the sovereignty over the Pole._______(49)"Doesn't he already speak Danish?"Boldt said frostily when asked if Father Christmas would be forced to learn Danish if Denmark won international recognition of its claim to the Pole.Last month's Arctic report said the region is warming twice as fast as the rest of the globe,partly because dark ground or water,once uncovered,soaks up more heat than ice or snow. Finland has been most favored by Father Christmas and it has about 500,000 tourists a year to visit its Christmas center in Rovaniemi in Lapland._______(50) __________(50)
[多选题]共用题干 Robotic Highway ConesA University of Nebraska professor has developed robotic cones and barrels.These robotic cones and barrels can move out of the way,or into______(51),from computer commands made miles away. They can even be programmed to move on their own at any particular part of the day,said Shane Farritor,an assistant professor of mechanical engineering at Nebraska.For example,if workers arrived at 6 am,the cones could move from the side of the highway to______(52)off the lane at that time.And they can return to the______(53)place at the end of the day."It just seems like a very good application for robots."Farritor said."The robot-ic cones would also help______(54)people from hazardous jobs on the highway putting barrels and cones into place,"Farritor said in a report on his creation.Work on the idea began in 2002 using a National Academy of Sciences grant. The______ (55)allowed Farritor to work on the project with graduate students at Nebraska and his assistant Steve Goddard.The robots are placed at the bottom of the cones and barrels and are______(56)enough not to greatly change the appearance of the construction aides."It would look exactly the same," Farritor said."______(57)there's a kind of rubbery,black base to them. We replace that ______(58)a robot."Farritor has talked with officials from the Nebraska Department of Roads about how the robots would be most______(59)to what they might need.The robots could come in handy following a slow-moving maintenance operation,like paint-ing a stripe on a road or moving asphalt,______(60)now the barrels have to be picked up and moved as the operation______(61)."That way you don't have to block off a 10-mile strip for the operation,"Farritor said.______(62)prototypes have been made,they are not in use anywhere. Farritor said he has______(63)for a patent and is considering what to do next. He is thinking about starting a small business. He is also thinking about______(64)the robots to roads departments and others across the country who may______(65)from them. 65._________
[多选题]共用题干 Better Solar Energy Systems: More Heat, More LightSolar photovoltaic thermal energy systems,or PVTs,generate both heat and electricity,but until now they haven't been very good at the heat-generating part compared to a stand-alone solar thermal collector. That's because they operate at low temperatures to cool crystalline silicon solar cells,which lets the silicon generate more electricity but isn't a very efficient way to gather heat.That's a problem of economics. Good solar hot-water systems can harvest much more energy than a solar-electric system at a substantially lower cost. And it's also a space problem:photovol-taic cells can take up all the space on the roof,leaving little room for thermal applications.In a pair of studies,Joshua Pearce,an associate professor of materials science and engineer-ing,has devised a solution in the form of a better PVT made with a different kind of silicon.His research collaborators are Kunal Girotra from Thin Silicon in California and Michael Pathak and Stephen Harrison from Queen's University,Canada.Most solar panels are made with crystalline silicon,but you can also make solar cells out of amorphous silicon,commonly known as thin-film silicon.They don't create as much electricity, but they are lighter,flexible,and cheaper. And,because they require much less silicon,they have a greener footprint. Unfortunately,thin-film silicon solar cells are vulnerable to some bad-news physics in the form of the Staebler-Wronski effect."That means that their efficiency drops when you expose them to light-pretty much the worst possible effect for a solar cell,"Pearce explains,which is one of the reasons thin-film solar panels make up only a small fraction of the market.However,Pearce and his team found a way to engineer around the Staebler-Wronski effect by incorporating thin-film silicon in a new type of PVT. You don't have to cool down thin-film silicon to make it work.In fact,Pearce's group discovered that by heating it to solar-thermal operating temperatures,near the boiling point of water,they could make thicker cells that largely overcame the Staebler-Wronski effect. When they applied the thin-fulm silicon directly to a solar thermal en-ergy collector,they also found that by baking the cell once a day,they boosted the solar cell's e-lectrical efficiency by over 10 percent. PVTs are not efficient in______.
[多选题]共用题干 Thirst for OilWorldwide every day,we devour the energy equivalent of about 200 million barrels of oil.Most of the energy on Earth comes from the Sun.In fact enough energy from the Sun hits the planet's surface each minute to cover our needs for an entire year,we just need to find an efficient way to use it. So far the energy in oil has been cheaper and easier to get at. But as supplies dwindle,this will change,and we will need to cure our addiction to oil.Burning wood satisfied most energy needs until the steam-driven industrial revolution,when energy-dense coal became the fuel of choice.Coal is still used,mostly in power stations,to cover one quarter of our energy needs,but its use has been declining since we started pumping up oil.Coal is the least efficient,unhealthiest and most environmentally damaging fossil fuel,but could make a comeback,as supplies are still plentiful:its reserves are five times larger than oil's.Today petroleum,a mineral oil obtained from below the surface of the Earth and used to pro- duce petrol,diesel oil and various other chemical substances,provides around 40% of the world's energy needs,mostly fuelling automobiles.The US consumes a quarter of all oil,and generates a similar proportion of greenhouse gas emissions.The majority of oil comes from the Middle East,which has half of known reserves.But other significant sources include Russia,North America,Norway,Venezuela and the North Sea.Alaska's Arctic National Wildlife Refuge could be a major new US source,to reduce reliance on foreign imports.Most experts predict we will exhaust easily accessible reserves within 50 years,though opinions and estimates vary.We could fast reach an energy crisis in the next few decades,when demand exceeds supply.As conventional reserves become more difficult to access,others such as oil shales and tar sands may be used instead.Petrol could also be obtained from coal.Since we started using fossil fuels,we have released 400 billion tonnes of carbon,and burn- ing the entire reserves could eventually raise world temperatures by 13℃.Among other horrors, this would result in the destruction of all rainforests and the melting of all Arctic ice. Which country is the biggest consumer of petroleum?
[多选题]共用题干 The Differences Among Various Types of AdoptionIn the US,there is a difference between public and private adoption.Public adoption typically involves taking _________ (51) foster(收养的)children and then adopting them after several months.It's significantly less expensive than private or international adoption,but more often than not_______(52)adopting children who are older than 5 or who have_______(53)needs.Private adoptions offer a better chance of adopting newborns,and increasingly,birth parents _______(54)the adoptive parents themselves.That's not a bad idea on its face,as it gives biological parents_______ (55)say in whom they will relinquish(放弃)their children. But this effectively puts_______(56)parents in the position of advertising themselves to birth parents in newspapers and online,_______(57)many couples feel uncomfortable with.Most states allow birth parents to reclaim their children_______(58)the children have been placed with adoptive families,for time periods ranging from a few days in some states to several months in others.Critics of international adoption say this rarely happens.They are only_______ (59)right:it's true that American birth parents don't usually reclaim their children once they've been placed with their adoptive families,but they can and do_______(60)their minds before the papers are signed.International adoption is more expensive than any form of domestic adoption,but in many ways, it is also more straightforward.The_______(61)of a birth parent calling the adoption_______ (62)are effectively zero and while costs are high,they're also determined at the_______(63) and tend not to change as the_______(64)wears on.Couples seeking to adopt should consider all_______(65)and get a range of perspectives before deciding which method is best for them. _________(55)
[多选题]共用题干 A Special JourneyI am often asked to describe the experience of_______(51)a child with a disability一to try to help people who have not shared that unique experience to understand it,to imagine how it would feel.It's like this…_______(52)you're going to have a baby,it's like planning a fabulous vacation trip to Italy. You buy a bunch of guide books and make your wonderful_______(53).The Coliseum,the Michelangelo,David,the gondolas in Venice.You may learn some handy phrases in Italian. It's all very exciting.After months of eager anticipation,the day finally_______(54).You pack your bags and _______(55)you go.Several hours later,the plane lands.The_______(56)comes in and says,"Welcome to Holland.""Holland?"you say."What do you mean by Holland?I signed up for Italy!I'm supposed to be in Italy. All my life I've dreamed_______(57)going to Italy."But there's been a change in the flight plan.They've landed in Holland and there you must stay.The important thing is that they haven't taken you to a horrible,disgusting,filthy place,full of pestilence,_______(58)and disease.It's just a_______(59)place._______(60)you must go out and buy new guide books.And you must learn a whole new language.And you will meet a whole new group of people you would never have met.It's just a different place.It's slower-paced than Italy,less flashy than Italy. But after you've been there for a while and you catch your breath,you look around…and you begin to_______ (61)that Holland has windmills…and Holland has tulips.Holland even has Rembrandts.But everyone you know is busy coming and going_______(62)Italy…and they're all bragging about_______(63)a wonderful time they had there. And for the rest of your life,you will say"Yes,that's where I was_______(64)to go.That's what I had planned."But if you spend your life_______(65)the fact that you didn't get to Italy,you may never be free to enjoy the very special,the very lovely things about Holland. _________(57)
[多选题]共用题干 Solar Power Without Solar CellsA dramatic and surprising magnetic effect of light discovered by University of Michigan researchers could lead to solar power without traditional semiconductor-based solar cells.The researchers found a way to make an"optical________(51)",said Stephen Rand,a professor in the departments of Electrical Engineering and Computer Science,Physics and Applied Physics.Light has electric and magnetic_______(52).Until now,scientists thought the effects of the mag-netic field were so weak that they could be________(53).What Rand and his colleagues found is that at the right intensity,when light is traveling through a material that does not_________(54)electricity,the light field can generate magnetic effects that are 100 million times stronger than previously expected.Under these circumstances,the magnetic effects develop strength_________(55)to a strong electric effect."This could lead to a new kind of solar cell without semiconductors and without absorption to produce charge separation,"Rand said."In solar cells,the_________(56)goes into a matenal,gets absorbed and creates heat.Here,we expect to have a very low heat load.Instead of the light being absorbed,energy is stored in the magnetic moment.Intense magnetization can be induced by intense light and then it is ultimately capable of providing a capacitive power________(57)."What makes this possible is a previously unde- tected brand of"optical rectification",says William Fisher,a doctoral student in applied physics.In tradi- tional optical rectification,light's electric field causes a charge separation,or a pulling_________(58)of the positive and negative charges in a material.This sets up a voltage,similar to______(59)in a battery.Rand and Fisher found that under the right circumstances and in right types of materials,the light's magnetic field can also create optical rectification.The light must be shone through a________(60)that does not conduct electricity,such as glass.And it must be focused to an intensity of 10 million watts per square centimeter. Sunlight isn't this_______(61)on its own,but new materials are being sought that would work at lower intensities,Fisher said."In our most recent paper,we show that incoherent light like sunlight is theoretically almost _________(62)effective in producing charge separation as laser light is,"Fisher said.This new_________(63)could make solar power cheaper,the researchers say.They predict that with improved materials they could achieve 10 percent efficiency in converting solar power to usable energy.That's equivalent to today's commercial-grade solar cells."To manufacture modern solar cells,you have to do. _______(64)semiconductor processing,"Fisher said."All we would need are lenses to focus the light and a fiber to guide it.Glassworks for _________ (65).It's already made in bulk,and it doesn't require as much processing.Transparent ceramics might be even better." _________(55)
[多选题]共用题干 The World's Longest BridgeRumor has it that a legendary six-headed monster lurks in the deep waters of the Tyrrhenian Sea between Italy and the island of Sicily._______(46)When completed in 2010,the world's longest bridge will weigh nearly 300,000 tons一equivalent to the iceberg that sank the Titanic一and stretch 5 kilometers long."That's nearly 50 percent longer than any other bridge ever built."says structural engineer Shane Rixon._______(47)They're suspension bridges,massive structures built to span vast water channels or gorges.A suspension bridge needs just two towers to shoulder the structure's mammoth weight, thanks to hefty supporting cables slung between the towers and anchored firmly in deep pools of cement at each end of the bridge.The Messina Strait Bridge will have two 54,100-ton towers,which will support most of the bridge's load.The beefy cables of the bridge,each 1.2 meter in diameter, will hold up the longest and widest bridge deck ever built.When construction begins on the Messina Strait Bridge in 2005,the first job will be to erect two 370 meter-tall steel towers._______(48)Getting these cables up will be something. It's not just their length一totally 5.3 kilometers一but their weight._______(49)After lowering vertical"suspender"cables from the main cables,builders will erect a 60- meter一wide 54,630一ton steel roadway,or deck一wide enough to accommodate 12 lanes of traffic.The deck's weight will pull down on the cables with a force of 70,500 tons.In return,the cables yank up against their firmly rooted anchors with a force of 139,000 tons一equivalent to the weight of about 100,000 cars. Those anchors are essential._______(50) _______(48)
[多选题]共用题干 The Impact of Antarctic Ozone HoleThe Antarctic ozone(臭氧)hole is changing weather patterns across the Southern Hemisphere (半球),even affecting the tropics,scientists have concluded. The scientists______(51)the new study added the ozone hole into standard climate models to_______(52)how it might have affected winds and rains. They say rainfall has moved further south towards the pole and the effect has been_______(53)strong over Australia.And of_______(54)interest was the southward of the Southern Hemisphere jet stream. These high一altitude winds are_______(55)to determining weather patterns,in both hemispheres. Much of the cold weather felt in the UK_______(56)the last couple of winters,for example,was caused by blocking of the Northern Hemisphere stream.The team found that overall,the ozone hole has_______(57)in rainfall moving south along with the winds._______(58)there are regional differences,particularly concerning Australia. In terms of the average for that zone,the ozone hole_______(59)about a 10% change一but for Australia,it's about 35%.Their modeling indicated that global warming_______(60)greenhouse gas emissions is also a factor in changing rainfall patterns.Natural climate cycles are also thought to be important here,as different rainfall patterns were _______(61)in the era before ozone depletion(消耗)and late 20th Century warming.Although the_______(62)international organization has significantly checked emissions of harmful substances,they_______(63)for decades in the atmosphere,and so their effects are still being felt.Earlier,and international organization forecast that even the Antarctic ozone hole一which is more severe than its_______(64)in the Northern Hemisphere一should be_______(65)by 2045—2060. _________(58)
[多选题]共用题干 The Cold PlacesThe Arctic is a polar region.It surrounds the North Pole.Like Antarctica,the Arctic is a land of ice and snow.Antarctica holds the record for a low temperature reading-125 degrees Fahrenheit below zero. Reading of 85 degrees below zero is common in both the Arctic and Antarctica.Winter temperatures average 30 degrees below zero in the Arctic .At the South Pole the winter average is about 73 degrees below zero.One thing alone makes it almost impossible for men to live in Antarctica and in parts of the Arctic .This one thing is the low temperature-the killing chill of far North and the polar South.To survive,men must wear the warmest possible clothing. They must build windproof shelters .They must keep heaters going at all times.Not ever for a moment can they be unprotected against the below-zero temperatures.Men have a way of providing for themselves.Polar explorers wrap themselves in warm coats and furs .The cold makes life difficult. But the explorers can stay alive.What about animals?Can they survive?Do we find plants?Do we find life in the Arctic and in Antarctica?Yes,we do. There is life in the oceans.There is life on land.Antarctica,as we have seen,is a cold place indeed.But this has not always been the case.Expedition scientists have discovered that Antarctica has not always been a frozen continent. At one time the weather in Antarctica may have much like our own.Explorers have discovered coal in Antarctica. This leads them to believe that Antarctica at one time was a land of swamps and forests.Heat and moisture must have kept the trees in the forests alive. Despite the hostile environment,both animals and plants can be found in the oceans and on land in polar areas.
[多选题]共用题干 Robotic Highway ConesA University of Nebraska professor has developed robotic cones and barrels.These robotic cones and barrels can move out of the way,or into______(51),from computer commands made miles away. They can even be programmed to move on their own at any particular part of the day,said Shane Farritor,an assistant professor of mechanical engineering at Nebraska.For example,if workers arrived at 6 am,the cones could move from the side of the highway to______(52)off the lane at that time.And they can return to the______(53)place at the end of the day."It just seems like a very good application for robots."Farritor said."The robot-ic cones would also help______(54)people from hazardous jobs on the highway putting barrels and cones into place,"Farritor said in a report on his creation.Work on the idea began in 2002 using a National Academy of Sciences grant. The______ (55)allowed Farritor to work on the project with graduate students at Nebraska and his assistant Steve Goddard.The robots are placed at the bottom of the cones and barrels and are______(56)enough not to greatly change the appearance of the construction aides."It would look exactly the same," Farritor said."______(57)there's a kind of rubbery,black base to them. We replace that ______(58)a robot."Farritor has talked with officials from the Nebraska Department of Roads about how the robots would be most______(59)to what they might need.The robots could come in handy following a slow-moving maintenance operation,like paint-ing a stripe on a road or moving asphalt,______(60)now the barrels have to be picked up and moved as the operation______(61)."That way you don't have to block off a 10-mile strip for the operation,"Farritor said.______(62)prototypes have been made,they are not in use anywhere. Farritor said he has______(63)for a patent and is considering what to do next. He is thinking about starting a small business. He is also thinking about______(64)the robots to roads departments and others across the country who may______(65)from them. 64._________
[多选题]共用题干 Historic Route 66:The Story of America's"Mother Road"1. The idea for Route 66 started in Oklahoma.Citizens there wanted to link their state with states to the east and west.By the l920s,federal officials wanted to connect state roads to provide a shorter,faster way across the country.So a plan was developed to connect existing state roads into one long national highway.2. United States Highway 66 was established on November 11,1926.It was one of the first federal highways .It crossed eight states.It was 3,800 kilometers long.Route 66 became the most famous road in America.It passed through the center of many cities and towns. It crossed deserts, mountains,valleys and rivers.3. In the 1930s,people suffered through the Great Depression.In Oklahoma,many poor families lost their farms because of dust storms.So they traveled west to California on Route 66 in search of a better life.In 1939,John Steinbeck wrote about these families in"The Grapes of Wrath."4. In his book,Steinbeck wrote:"66-the long concrete path across the country,waving gently up and down on the map,over the red lands and the gray lands,twisting up into the mountains, crossing the Divide and down into the bright and terrible desert,and across the desert to the mountains again,and into the rich California valleys."Steinbeck wrote:"66 is the path of a people in flight,refugees from dust and shrinking land.66 is the mother road,the road of flight."5. In 1946,the songwriter Bobby Troup and his wife drove across the country to Los Angeles.He wrote a song about traveling on Route 66 .The song told people they could have fun,could get their kicks,on that drive.In Los Angeles,Bobby Troup took the song to Nat King Cole,who recorded it. It became a huge hit.6. In the 1950s,holiday travel brought more and more families out West to explore.Route 66 represented the spirit of movement and excitement.In the 1960s,Americans watched a popular television series called"Route 66."It was the story of two young men driving across the country.The show was filmed in cities and towns across America.Yet only a few shows were filmed on the real Route 66.7. In real life,people were getting fewer and fewer kicks on Route 66.By 1962,parts of the road were closed because they were in poor condition.The federal government was building bigger highways .Cars and trucks could travel at higher speeds. People started driving on these new interstate highways instead of the old Route 66 .Finally,in 1985,Route 66 was officially removed from the national highway system.People have formed groups to save parts of the old 66 and many of the interesting places to eat,stay and see along the way. Paragraph 7______
[多选题]共用题干 InflationBusiness and government leaders also consider the inflation rate to be an important general indicator. Inflation is a period of increased spending that causes rapid rises in prices._______(51)your money buys fewer goods so that you get_______(52)for the same amount of money as before,inflation is the problem. There is a general rise_______(53)the price of goods and services.Your money buys less.Sometimes people describe inflation as a time when"a dollar is not worth a dollar anymore".Inflation is a problem for all consumers.People who live on a fixed income are hurt the _______(54).Retired people,for instance,cannot count on an increase in income as prices rise. Elderly people who do not work face serious problems in stretching their incomes to_______(55) their needs in time of inflation.Retirement income_______(56)any fixed income usually does not rise as fast as prices.Many retired people must cut their spending to_______(57)rising prices.In many cases they must stop_______(58)some necessary items,such as food and clothing. Even _______(59)working people whose incomes are going up,inflation can be a problem. The_______(60)of living goes up,too. People who work must have even more money to keep up their standard of living. Just buying the things they need costs more.When incomes do not keep _______(61)with rising prices,the standard of living goes down.People may be earning the same amount of money,but they are not living as well because they are not able to buy as many goods and services.Government units gather information about prices in our economy and publish it as price indexes _______(62)the rate of change can be determined.A price index measures changes in prices using the price for a_______(63)year as the base.The base price is set at 100,and the other prices are reported as a_______(64)of the base price.A price index makes_______(65)possible to compare current prices of typical consumer goods,for example,with prices of the same goods in previous years. _________(56)

相关课程