理工类

考试试题

[多选题]共用题干 第一篇Forecasting MethodsThere are several different methods that can be used to create a forecast. The method a forecaster chooses depends upon the experience of the forecaster,the amount of information available to the forecaster,the level of difficulty that the forecast situation presents,and the degree of accuracy or confidence needed in the forecast.The first of these methods is the persistence method,the simplest way of producing a forecast.The per- sistence method assumes that the conditions at the time of the forecast will not change.For example,if it is sunny and 87 degrees today,the persistence method predicts that it will be sunny and 87 degrees tomorrow. If two inches of rain fell today,the persistence method would predict two inches of rain for tomorrow. However,if weather conditions change significantly from day to day,the persistence method usually breaks down and is not the best forecasting method to use.The trends method involves determining the speed and direction of movement for fronts,high and low pressure centers , and areas of clouds and precipitation(降水量).Using this information , the forecaster can predict where he or she expects those features to be at some future time.For example,if a storm system is 1,000 miles west of your location and moving to the east at 250 miles per day,using the trends method you would predict it arrive in your area in 4 days.The trends method works well when systems continue to move at the same speed in the same direction for a long period of time.If they slow down,speed up,change intensi- ty,or change directions,the trends forecast will probably not work as well.The climatology(气候学)method is another simple way of producing a forecast. This method involves averaging weather statistics accumulated over many years to make the forecast.For example,if you were using the climatology method to predict the weather for New York City on July 4th,you would go through all the weather data that has been recorded for every July 4th and take an average.The climatology method oniy works well when the weather pattern is similar to that expected for the chosen time of year. If the pattern is quite unusual for the given time of year,the climatology method will often fail.The analog method is a slightly more complicated method of producing a forecast.It involves examining today's forecast scenario(模式)and remembering a day in the past when the weather scenario looked very similar(an analog).The forecaster would predict that the weather in this forecast will behave the same as ii did in the past.The analog method is difficult to use because it is virtually impossible to find a predict ana- log.Various weather features rarely align themselves in the same locations as they were in the previous time. Even small differences between the current time and the analog can lead to very different results. The trends method works well when_________.
[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 The Day a Language DiedWhen Carlos Westez died at the age of 76,a language died,too.Westez,more commonly known as Red Thunder Cloud,was the last speaker of the Native American language,Catawba.Anyone who wants to hear various songs of the Catawba can contact the Smithsonian Institution in Washington,D.C.,where, back in the 1940s,Red Thunder Cloud recorded a series of songs for future generations.______(46) They are all that is left of the Catawba language.The language that people used to speak is gone forever.We are all aware of the damage that modern industry can do to the world's ecology(生态).However, few people are aware of the impact that widely spoken languages have on other languages and ways of life.English has spread all over the world.Chinese,Spanish,Russian,and Hindi have become powerful languages,as well.______(47)When this happens,hundreds of languages that are spoken by only a few people die out.Scholars believe there are about 6 ,000 languages around the world,but more than half of them could die out within the next 100 years.There are many examples.Araki is a native language of the island of Vanuatu,located in the Pacific Ocean.It is spoken by only a few older adults,so like Catawba,Araki will soon disappear.Many languages of Ethiopia will have the same fate because each one has only a few speakers.______(48)In the Americas,100 languages,each of which has fewer than 300 speakers,also are dying out.Red Thunder Cloud was one of the first to recognize the threat of language death and to try to do something about it.He was not actually born into the Catawba tribe,and the language was not his mother tongue.______(49)The songs he sang for the Smithsonian Institution helped to make Native American music popular.Now he is gone,and the language is dead.What does it mean when a language disappears? When a plant or insect or animal species dies,it is easy to understand what we've lost and to appreciate what this means for the balance of the natural world.However,language is only a product of the mind.To be the last remaining speaker of a language,like RedThunder Cloud,must be a lonely destiny,almost as strange and terrible as being the last surviving member of a dying species.______(50) _______(50)
[多选题]共用题干 Chimpanzees1 Chimpanzees(黑猩猩)will soon be extinct(灭绝).If the present rate of hunting and habitat(栖息地)destruction continues, then within 20 years, there will be no chimpanzees living in the wild. But this is more than an environmental or moral tragedy(悲剧).Chimpan-zee extinction may also have profound implications(含意)for the survival of their distant relatives一human beings.2 In 1975 the biologist Marie-Claire King and Allan Wilson discovered that the human and chimpanzee genomes(基因组)match by over 98%. Compare this to the mouse, used as model for human disease in lab tests,which shares only 60% of its DNA with us.In fact, chimpanzees are far more similar to humans than they are to any other species of monkey. As well as resembling us genetically,chimps are highly intelligent and able to use tools.These facts alone should be enough to make protection of chimps an urgent priority(优先).But there is another,more selfish reason to preserve the chimp.3 The chimpanzees' trump card(王牌)comes in the field of medical research. Chimpan-zees are so similar to humans that veterinarians(兽医)often refer to human medical text-books when treating them. Yet chimpanzees do show differences in several key areas.In parti-cular,chimps are much more resistant to a number of major diseases.It is this ability that is so interesting.4 For example,chimps seem to show a much higher resistance than humans to HIV,the virus that causes AIDS. Indeed,their use as experimental animals in AIDS research has de-clined because they are so resistant.5 By sequencing the chimp genome and pinpointing(找到)the place where the chimpan-zee DNA sequence differs from that of humans,scientists hope to be able to discover which part of the genetic code gives chimps their increased resistance to some diseases. This,they hope,will allow them to develop new and more effective treatments for the human forms of these diseases. Such treatments could include the production of new drugs or even the altera-tion(改变)of the human genetic sequence. The recently completed human genome sequen-cing project has shown that such an effort is now well within our reach. Paragraph 4______.
[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. _________(55)
[多选题]共用题干 Ford1 Ford's great strength was the manufacturing process一not invention.Long before he started a car company,he was a worker,known for picking up pieces of metal and wire and turning them into machines.He started putting cars together in 1891.Although it was by no means the first popular automobile,the Model T showed the world just how creative Ford was at combining technology and market.2 The company's assembly line alone threw America's Industrial Revolution into overdrive (高速运转).Instead of having workers put together the entire car , Ford's friends , who were great toolmakers from Scotland,organized teams that added parts to each Model T as it moved down a line. By the time Ford's Highland Park plant was humming(嗡嗡作响) along in 1914,the world's first automatic conveyor belt could turn out a car every 93 minutes.3 The same year Henry Ford shocked the world with the$5-a-day minimum wage scheme,the greatest contribution he had ever made. The average wage in the auto industry thenwas $2.34 for a 9-hour shift. Ford not only doubled that,he also took an hour off the workday.In those years it was unthinkable that a man could be paid that much for doing something that didn't involve an awful lot of training or education.The Wall Street Journal called the plan"an economic crime",and critics everywhere laughed at Ford.4 But as the wage increased later to daily$10,it proved a critical component of Ford's dream to make the automobile accessible(可及的)to all. The critics were too stupid to understand that because Ford had lowered his costs per car,the higher wages didn't matter一 except for making it possible for more people to buy cars. Paragraph 1_______
[多选题]共用题干 第三篇“Life Form Found" on Saturn ' s TitanScientists say they have discovered hints of alien life on the Saturn'5 moon.The discovery of a sort of life was announced after researchers at the US space agency,NASA,analyzed data from spacecraft Cassini, which pointed to the existence of methane-based form of life on Saturn's biggest moon.Scientists have reportedly discovered clues showing primitive alien beings are"breathing"in Titan's dense atmosphere filled with hydrogen.They argue that hydrogen gets absorbed before hitting Titan's planet-like surface covered with methane lakes and rivers.This,they say,points to the existence of some"bugs"consuming the hydrogen at the surface of the moon less than half the size of the Earth."We suggested hydrogen consumption because it's the obvious gas for life to consume on Titan,similar to the way we consume oxygen on Earth,"says NASA scientist Chris McKay."If these signs do turn out to be a sign of life,it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth."To date,scientists have not yet detected this form of life anywhere,though there are liquid-water-based microorganisms on Earth that grow well on methane or produce it as a waste product. On Titan,wheretemperatures are around minus 17 Kelvin(minus 290 degrees Farenheit),a methane-based organism would have to use a substance that is liquid as its medium for living processes,but not water itself. Water is frozen solid on Titan'5 surface and much too cold to support life as we know it.Scientists had expected the Sun'5 interactions with chemicals in the atmosphere to produce a coating of acetylene on Titan'5 surface.But Cassini detected no acetylene on the surface.The absence of detectable acetylene on the Titan's surface can very well have a non-biological explana-tion,said Mark Allen,a principal investigator of the NASA Titan team."Scientific conservatism suggests that a biological explanation should be the last choice after all non- biological explanations are addressed,"Allen said."We have a lot of work to do to rule out possible non-bio- logical explanations.It is more likely that a chemical process,without biology,can explain these results." It can be inferred from Mark Allen's address that_____________.
[多选题]共用题干 Cloning(克隆):Future Perlect?1 A clone is an exact copy of a plant or animal produced from any one cell.Since Scottish scientists reported that they had managed to clone a sheep named Dolly in 1997,research into cloning has grown rapidly.In May 1998,scientists in Massachusetts managed to create two identical calves(牛犊)using cloning technology. A mouse has also been cloned successfully.But the debate over cloning humans really started when Chicago physicist Richard Seed made a surprising announcement:"We will have managed to clone a human being within the next two years."he told the world.2 Seed's announcement provoked a lot of media attention,most of it negative,In Europe, nineteen nations have already signed an agreement banning human cloning and in the U.S. the President announced:"We will be introducing a law to ban all human cloning and many states in the U. S. will have passed anti-cloning laws by the end of the year."3 Many researchers are not so negative about cloning.They are worried that laws banning human cloning will threaten important research.In March,The New England Journal of Medicine called any plan to ban research on cloning humans seriously mistaken.Many researchers also believe that in spite of attempts to ban it,human cloning will have become routine by 2010 because it is impossible to stop the progress of science.4 Is there reason to fear that cloning will lead to a nightmare world?The public has been bombarded(轰炸)with newspaper articles, television shows and films, as well as cartoons.Such information is often misleading,and makes people wonder what on earth the scientists will be doing next.5 Within the next five to ten years scientists will probably have found a way of cloning humans.It could be that pretty soon we will be able to choose the person that we want our child to look like,But how would it feel to be a clone among hundreds,the anti-cloners ask. Pretty cool, answer the pro-cloners(赞成克隆的人). Richard Seed's announcement received_______.
[多选题]共用题干 Underground Coal FiresCoal burning deep underground in China,India and Indonesia is threatening the environment and human life , scientists have warned.These large-scale______(51)blazes(火焰)cause the ground temperature to heat up and kill surrounding vegetation,produce greenhouse gases and can______(52) ignite(点燃)forest fires , a group of scientists told the annual meeting of the American Association for theAdvancement of Science in Denver.The resulting______(53)of poisonous elements like mercury can also pollute local water sources and soils,they warned."Coal fires are a global disaster,"said Associate Professor Glenn Stracher of East Georgia College inSwainsboro,USA.But______(54)few people know about them.Coal can heat up on its own,and eventually catch fire and bum,if there is a continuous oxygen supply.The heat produced is not caused to______(55)and under the right combinations of sunlight and oxygen,can trigger spontaneous(自发的)catching fire and buming.This can occur underground , in coal stockpiles, abandoned mines or even as coal is transported.______(56)fires in China consume up to 200 million tons of coal per year,delegates were told.In______(57),the U.S.economy consumes about one billion tons of coal annually,said Stracher,______(58)analysis of the likely impact of coal fires has been accepted for publication in the International Journal of Coal Ecology.______(59)underway,coal fires can bum for decades,even centuries.In the process,they release large______(60)of greenhouse gases,poisonous fumes and black particles into the atmosphere.The members of the panel discussed the______(61)these fires may be having on global and regional climate change,and agreed that the underground nature of the fires makes them difficult to______(62).Ultimately,the remote sensing and other techniques should allow scientists to______(63)how much carbon dioxide these fires are emitting(释放).One suggested______(64)of containing the fires was presented by Gary Colaizzi,of the engineering firm Goodson,which has developed a heat-resistant grout(灌浆),which is designed to be pumped into the coal fire to______(65)the oxygen supply. _________57
[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. __________(50)
[多选题]共用题干 Climate Change Poses Major Risks for Unprepared CitiesA new examination of urban policies has been carried out recently by Patricia Romero Lankao. She is a so- ciologist specializing in climate change and_____________(51) development. She warns that many of the world'5 fast-growing urban areas,especially in developing countries,will likely suffer from the_____________(52)of changing climate. Her work also concludes that most cities are failing to_____________(53)emissions of carbon dioxide and other greenhouse gases. These gases are known to affect the atmosphere."Climate change is a deeply local issue and poses profound_____________ (54) to the growing cities of the world,"says Romero Lankao. "But too few cities are developing effective strategies to protect their residents."Cities are_____________(55)sources of greenhouse gases.And urban populations are likely to be among those most severely affected by future climate change.Lankao's findings highlight ways in which city-resi- dents are particularly vulnerable,and suggest policy interventions that could offer immediate and longer-term ____________ (56).The locations and dense construction patterns of cities often place their populations at greater _____________(57)for natural disasters.Potential threats associated with climate include storm surges and pro- longed hot weather. Storm surges can flood coastal areas and prolonged hot weather can heat_____________(58) paved cities more than surrounding areas. The impacts of such natural events can be more_____________(59)in an urban environment. For example,a prolonged heat wave can increase existing levels of air pollution,causing widespread health problems.Poorer neighborhoods that may_____________(60)basic facilities such as drinking water or a dependable network of roads,are especially vulnerable to natural disasters.Many residents in poorer countries live in substandard housing_____________(61)access to reliable drinking water,roads and basic services.Local governments,therefore,should take measures to_____________(62)their residents."Unfortunately, they tend to move towards rhetoric_____________(63)meaningful responses,"Romero Lankao writes,"They don't impose construction standards that could reduce heating and air conditioning_____________(64).They don't em- phasize mass transit and reduce automobile use.In fact,many local governments are taking a hands-off ap- proach."_____________(65),she urges them to change their idle policies and to take strong steps to prevent the harmful effects of climate change on cities. _________(65)
[多选题]共用题干 Chimpanzees1 Chimpanzees(黑猩猩)will soon be extinct(灭绝).If the present rate of hunting and habitat(栖息地)destruction continues, then within 20 years, there will be no chimpanzees living in the wild. But this is more than an environmental or moral tragedy(悲剧).Chimpan-zee extinction may also have profound implications(含意)for the survival of their distant relatives一human beings.2 In 1975 the biologist Marie-Claire King and Allan Wilson discovered that the human and chimpanzee genomes(基因组)match by over 98%. Compare this to the mouse, used as model for human disease in lab tests,which shares only 60% of its DNA with us.In fact, chimpanzees are far more similar to humans than they are to any other species of monkey. As well as resembling us genetically,chimps are highly intelligent and able to use tools.These facts alone should be enough to make protection of chimps an urgent priority(优先).But there is another,more selfish reason to preserve the chimp.3 The chimpanzees' trump card(王牌)comes in the field of medical research. Chimpan-zees are so similar to humans that veterinarians(兽医)often refer to human medical text-books when treating them. Yet chimpanzees do show differences in several key areas.In parti-cular,chimps are much more resistant to a number of major diseases.It is this ability that is so interesting.4 For example,chimps seem to show a much higher resistance than humans to HIV,the virus that causes AIDS. Indeed,their use as experimental animals in AIDS research has de-clined because they are so resistant.5 By sequencing the chimp genome and pinpointing(找到)the place where the chimpan-zee DNA sequence differs from that of humans,scientists hope to be able to discover which part of the genetic code gives chimps their increased resistance to some diseases. This,they hope,will allow them to develop new and more effective treatments for the human forms of these diseases. Such treatments could include the production of new drugs or even the altera-tion(改变)of the human genetic sequence. The recently completed human genome sequen-cing project has shown that such an effort is now well within our reach. Scientists suspect that genes play a significant role in protecting chimps from getting______.
[多选题]共用题干 Cloning(克隆):Future Pertect?1 A clone is an exact copy of a plant or animal produced from any one cell.Since Scottish scientists reported that they had managed to clone a sheep named Dolly in 1997,research into cloning has grown rapidly.In May 1998,scientists in Massachusetts managed to create two identical calves(牛犊)using cloning technology. A mouse has also been cloned successfully.But the debate over cloning humans really started when Chicago physicist Richard Seed made a surprising announcement:"We will have managed to clonen a human being within the next two years."he told the world.2 Seed's announcement provoked a lot of media attention,most of it negative.In Europe, nineteen nations have already signed an agreement banning human cloning and in the U.S. the President announced:"We will be introducing a law to ban all human cloning and many states in the U.S. will have passed anti-cloning laws by the end of the year."3 Many researchers are not so negative about cloning.They are worried that laws banning human cloning will threaten important research.In March,The New England Joumal of Medicine called any plan to ban research on cloning humans seriously mistaken.Many researchers also believe that in spite of attempts to ban it,human cloning will have become routine by 2010 because it is impossible to stop the progress of science.4 Is there reason to fear that cloning will lead to a nightmare world?The public has been bombarded(轰炸)with newspaper articles , television shows and films , as well as cartoons.Such information is often misleading,and makes people wonder what on earth the scientists will be doing next.5 Within the next five to ten years scientists will probably have found a way of cioning humans.It could be that pretty soon we will be able to choose the person that we want our child to look like.But how would it feel to be a clone among hundreds,the anti-cloners ask. Pretty cool , answer the pro-cloners(赞成克隆的人). Richard Seed's announcement received_________.
[多选题]共用题干 Ecosystem1. The word “ecosystem” is short for ecological(生态的)system. An ecosystem is where living creatures expand within a given area. You can say that an ecosystem is the natural environment where biological organisms(生物)such as plants,animals and humans co-exist in this world. So naturally that includes you and me. Yes,we are all members of an ecosystem!2 .There are different kinds of ecosystems depending on the type of surface or environ-ment. Most are naturally made such as the ocean or lake and the desert or rainforest.Some are man-made or artificial to encourage co-habitation(同居)between living and non-living things in a monitored environment,such as a zoo or garden.3 .Plants make up the biggest group of biological creatures within an ecosystem,and that's because they are the natural food producers for everyone. Plants raised in the earth need air and collect sunlight to help them grow. When they grow,the plants and its fruits or flowers eventually become a source of food to animals,microorganisms(微生物)and even hu- mans,of course. Food is then converted to energy for the rest of us to function,and this hap-pens in a never-ending cycle until the living creatures die and break up back in the earth.4 .Ecosystems are the basis of survival for all living things.We depend on plants and ani-mals for food. In order for us to exist,we need to grow and care about other organisms. We also need to care for the non-living things within our environment like our air and water so we can continue living as a population. Since plants,animals and humans are all of various species(物种),we all play a role in maintaining the ecosystem.5 .To preserve our ecosystems,we should stop using too much energy,which happens when we consume more than our share of resources. Humans should not disturb the natural habitat(栖息地)of plants and animals,and allow them to grow healthily for the cycle to con-tinue. Too many people in a habitat can mean displacement(搬迁): imagine being thrown out of your home because there is no more space for everyone. Worse,overpopulation can also ru- in the environment and cause destruction of existing plants and animals. In an ecosystem,plants,animals and humans live together in______.
[多选题]共用题干 Chimpanzees1 Chimpanzees(黑猩猩)will soon be extinct(灭绝).If the present rate of hunting and habitat(栖息地)destruction continues, then within 20 years, there will be no chimpanzees living in the wild. But this is more than an environmental or moral tragedy(悲剧).Chimpan-zee extinction may also have profound implications(含意)for the survival of their distant relatives一human beings.2 In 1975 the biologist Marie-Claire King and Allan Wilson discovered that the human and chimpanzee genomes(基因组)match by over 98%. Compare this to the mouse, used as model for human disease in lab tests,which shares only 60% of its DNA with us.In fact, chimpanzees are far more similar to humans than they are to any other species of monkey. As well as resembling us genetically,chimps are highly intelligent and able to use tools.These facts alone should be enough to make protection of chimps an urgent priority(优先).But there is another,more selfish reason to preserve the chimp.3 The chimpanzees' trump card(王牌)comes in the field of medical research. Chimpan-zees are so similar to humans that veterinarians(兽医)often refer to human medical text-books when treating them. Yet chimpanzees do show differences in several key areas.In parti-cular,chimps are much more resistant to a number of major diseases.It is this ability that is so interesting.4 For example,chimps seem to show a much higher resistance than humans to HIV,the virus that causes AIDS. Indeed,their use as experimental animals in AIDS research has de-clined because they are so resistant.5 By sequencing the chimp genome and pinpointing(找到)the place where the chimpan-zee DNA sequence differs from that of humans,scientists hope to be able to discover which part of the genetic code gives chimps their increased resistance to some diseases. This,they hope,will allow them to develop new and more effective treatments for the human forms of these diseases. Such treatments could include the production of new drugs or even the altera-tion(改变)of the human genetic sequence. The recently completed human genome sequen-cing project has shown that such an effort is now well within our reach. Paragraph 2______.
[多选题]共用题干 More Than 8 Hours Sleep Too Much of a Good Thing1 Although the dangers of too little sleep are widely known,new research suggests that people who sleep too much may also suffer the consequences.2 Investigators at the University of California in San Diego found that people who clock up 9 or 10 hours each weeknight appear to have more trouble falling and staying asleep,as well as a number of other sleep problems,than people who sleep 8 hours a night. People who slept only 7 hours each night also said they had more trouble falling asleep and feeling re-freshed after a night's sleep than 8-hour sleepers.3 These findings,which DL Daniel Kripke reported in the journal Psychosomatic Medicine,demonstrate that people who want to get a good night's rest may not need to set aside more than 8 hours a night.He added that“it might be a good idea” for people who sleep more than 8 hours each night to consider reducing the amount of time they spend in bed,but cau-tioned that more research is needed to confirm this.4 Previous studies have shown the potential dangers of chronic shortages of sleep一for instance,one report demonstrated that people who habitually sleep less than 7 hours each night have a higher risk of dying within a fixed period than people who sleep more.5 For the current report,Kripke reviewed the responses of 1,004 adults to sleep ques-tionaires,in which participants indicated how much they slept during the week and whether they experienced any sleep problems. Sleep problems included waking in the middle of the night,arising early in the morning and being unable to fall back to sleep,and having fatigue interfere with day-to-day functioning.6 Kripke found that people who slept between 9 and 10 hours each night were more like-ly to report experiencing each sleep problem than people who slept 8 hours. In an interview, Kripke noted that long sleepers may struggle to get rest at night simply because they spend too much time in bed. As evidence,he added that one way to help insomnia is to spend less time in bed.“It stands to reason that if a person spends too long a time in bed,then they'll spend a higher percentage of time awake.”he said. Paragraph 5______
[多选题]共用题干 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 shifted to 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(惰性气体).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 the heaviest.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 corn- 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 3____________
[多选题]共用题干 The Tough Grass That Sweetens Our LivesSugar cane was once a wild grass that grew in New Guinea and was used by local people for roofing their houses and fencing their gardens. Gradually a different variety evolved which contained sucrose(蔗糖)and was chewed on for its sweet taste. Over time,sugar cane became a highly valuable commercial plant,grownthroughout the world. _________(46)Sugar became a vital ingredient in all kinds of things ,from confectionery(糖果点心)to medicine , and, as the demand for sugar grew ,the industry became larger and more profitable.__________(47)Many crops withered(枯萎)and died,despite growers' attempts to save them ,and there were fears that the health of the plant would continue to deteriorate.In the 1960s ,scientists working in Barbados looked for ways to make the commercial species stronger and more able to resist disease. They experimented with breeding programmes,mixing genes from the wild species of sugar cane,which tends to be tougher, with genes from the more delicate,commercial type. ___________(48)This sugar cane is not yet ready to be sold commercially,but when this happens,it is expected to he incredibly profitable for the industry.____________ (49)Brazil , which produces one quarter of the world's sugar, has coordinated an intema- tional project under Professor Paulo Arrudo of the Universidade Estaudual de Campinas in Sao Paulo. Teams of experts have worked with him to discover more about which parts of the genetic structure of the plant are important for the production of sugar and its overall health.Despite all the research ,however, we still do not fully understand how the genes function in sugar cane.___________(50)This gene is particularly exciting because it makes the plant resistant to rust,a disease which probably originated in India,but is now capable of infecting sugar cane across the world.Scientists believe they will eventually be able to grow a plant which cannot be destroyed by rust. ________(49)
[多选题]共用题干 Cloning(克隆):Future Pertect?1 A clone is an exact copy of a plant or animal produced from any one cell.Since Scottish scientists reported that they had managed to clone a sheep named Dolly in 1997,research into cloning has grown rapidly.In May 1998,scientists in Massachusetts managed to create two identical calves(牛犊)using cloning technology. A mouse has also been cloned successfully.But the debate over cloning humans really started when Chicago physicist Richard Seed made a surprising announcement:"We will have managed to clonen a human being within the next two years."he told the world.2 Seed's announcement provoked a lot of media attention,most of it negative.In Europe, nineteen nations have already signed an agreement banning human cloning and in the U.S. the President announced:"We will be introducing a law to ban all human cloning and many states in the U.S. will have passed anti-cloning laws by the end of the year."3 Many researchers are not so negative about cloning.They are worried that laws banning human cloning will threaten important research.In March,The New England Joumal of Medicine called any plan to ban research on cloning humans seriously mistaken.Many researchers also believe that in spite of attempts to ban it,human cloning will have become routine by 2010 because it is impossible to stop the progress of science.4 Is there reason to fear that cloning will lead to a nightmare world?The public has been bombarded(轰炸)with newspaper articles , television shows and films , as well as cartoons.Such information is often misleading,and makes people wonder what on earth the scientists will be doing next.5 Within the next five to ten years scientists will probably have found a way of cioning humans.It could be that pretty soon we will be able to choose the person that we want our child to look like.But how would it feel to be a clone among hundreds,the anti-cloners ask. Pretty cool , answer the pro-cloners(赞成克隆的人). Paragraph 4_________
[多选题]共用题干 Ford1 Ford's great strength was the manufacturing process一not invention.Long before he started a car company,he was a worker,known for picking up pieces of metal and wireand turning them into machines.He started putting cars together in 1891.Although it was by no means the first popular automobile,the Model T showed the world just how creative Ford was at combining technology and market.2 The company's assembly line alone threw America's Industrial Revolution into overdrive (高速运转).Instead of having workers put together the entire car, Ford's friends, who were great toolmakers from Scotland,organized teams that added parts to each Model T as it moved down a line. By the time Ford's Highland Park plant was humming(嗡嗡作响) along in 1914,the world's first automatic conveyor belt could turn out a car every 93 minutes.3 The same year Henry Ford shocked the world with the$5-a-day minimum wage scheme,the greatest contribution he had ever made.The average wage in the auto industry then was$2.34 for a 9-hour shift.Ford not only doubled that,he also took an hour off the workday.In those years it was unthinkable that a man could be paid that much for doing something that didn't involve an awful lot of training or education.The Wall Street Journal called the plan"an economic crime",and critics everywhere laughed at Ford.4 But as the wage increased later to daily$10,it proved a critical component of Ford's dream to make the automobile accessible(可及的)to all. The critics were too stupid to understand that because Ford had lowered his costs per car,the higher wages didn'tmatter一except for making it possible for more people to buy cars. Paragraph 3_________
[多选题]共用题干 The Tough Grass That Sweetens Our LivesSugar cane was once a wild grass that grew in New Guinea and was used by local people for roofing their houses and fencing their gardens. Gradually a different variety evolved which contained sucrose(蔗糖)and was chewed on for its sweet taste. Over time,sugar cane became a highly valuable commercial plant,grownthroughout the world. _________(46)Sugar became a vital ingredient in all kinds of things ,from confectionery(糖果点心)to medicine , and, as the demand for sugar grew ,the industry became larger and more profitable.__________(47)Many crops withered(枯萎)and died,despite growers' attempts to save them ,and there were fears that the health of the plant would continue to deteriorate.In the 1960s ,scientists working in Barbados looked for ways to make the commercial species stronger and more able to resist disease. They experimented with breeding programmes,mixing genes from the wild species of sugar cane,which tends to be tougher, with genes from the more delicate,commercial type. ___________(48)This sugar cane is not yet ready to be sold commercially,but when this happens,it is expected to he incredibly profitable for the industry.____________ (49)Brazil , which produces one quarter of the world's sugar, has coordinated an intema- tional project under Professor Paulo Arrudo of the Universidade Estaudual de Campinas in Sao Paulo. Teams of experts have worked with him to discover more about which parts of the genetic structure of the plant are important for the production of sugar and its overall health.Despite all the research ,however, we still do not fully understand how the genes function in sugar cane.___________(50)This gene is particularly exciting because it makes the plant resistant to rust,a disease which probably originated in India,but is now capable of infecting sugar cane across the world.Scientists believe they will eventually be able to grow a plant which cannot be destroyed by rust. ________(47)
[多选题]共用题干 The iPad1 The iPad is a tablet computer(平板电脑)designed and developed by Apple. It is par-ticularly marketed as a platform for audio and visual media such as books,periodicals(期刊),movies,music,and games,as well as web content. At about 1 .5 pounds(680 grams), its size and weight are between those of most contemporary smartphones and laptop comput-ers.Apple released the iPad in April 2010,and sold 3 million of the devices in 80 days.2 The iPad runs the same operating system as iPod Touch and iPhone. It can run its own applications as well as ones developed for iPhone. Without modification,it will only run pro-grams approved by Apple and distributed via its online store.3 Like iPhone and iPod Touch,the iPad is controlled by a multitouch display一a break from most previous tablet computers, which uses a pressure-triggered stylus(触控笔).The iPad uses a Wi-Fi data connection to browse(浏览)the Internet, load and stream media, and install software. Some models also have a 3G wireless data connection which can connect to GSM 3G data networks. The devices is managed and synchronized(同步)by iTunes on a per-sonal computer via USB cable.4 An iPad has different features and applications one can use to execute different and in-teresting things. There are lots of iPad applications that the owner can use to enhance the way they communicate. Some of these are how to use social networking sites and other online options.One of the most common uses is for e-mail services. iPad applications like Markdown Mail allow the adoption of specific and particular options. They enable the owner to personal-ize their email accounts.5 While the iPad is mostly used by consumers it also has been taken up by business us-ers. Some companies are adopting iPads in their business offices by distributing or making available iPads to employees.Examples of uses in the workplace include lawyers responding to clients,medical professionals accessing health records during patient exams,and manag-ers approving employee requests.A survey by Frost Sullivan shows that iPad usage in work-places is linked to the goals of increased employees productivity,reduced paperwork,and in-creased revenue. Paragraph 5______
[多选题]共用题干 Climate Change Poses Major Risks for Unprepared CitiesA new examination of urban policies has been carried out recently by Patricia Romero Lankao. She is a so- ciologist specializing in climate change and_____________(51) development. She warns that many of the world'5 fast-growing urban areas,especially in developing countries,will likely suffer from the_____________(52)of changing climate. Her work also concludes that most cities are failing to_____________(53)emissions of carbon dioxide and other greenhouse gases. These gases are known to affect the atmosphere."Climate change is a deeply local issue and poses profound_____________ (54) to the growing cities of the world,"says Romero Lankao. "But too few cities are developing effective strategies to protect their residents."Cities are_____________(55)sources of greenhouse gases.And urban populations are likely to be among those most severely affected by future climate change.Lankao's findings highlight ways in which city-resi- dents are particularly vulnerable,and suggest policy interventions that could offer immediate and longer-term ____________ (56).The locations and dense construction patterns of cities often place their populations at greater _____________(57)for natural disasters.Potential threats associated with climate include storm surges and pro- longed hot weather. Storm surges can flood coastal areas and prolonged hot weather can heat_____________(58) paved cities more than surrounding areas. The impacts of such natural events can be more_____________(59)in an urban environment. For example,a prolonged heat wave can increase existing levels of air pollution,causing widespread health problems.Poorer neighborhoods that may_____________(60)basic facilities such as drinking water or a dependable network of roads,are especially vulnerable to natural disasters.Many residents in poorer countries live in substandard housing_____________(61)access to reliable drinking water,roads and basic services.Local governments,therefore,should take measures to_____________(62)their residents."Unfortunately, they tend to move towards rhetoric_____________(63)meaningful responses,"Romero Lankao writes,"They don't impose construction standards that could reduce heating and air conditioning_____________(64).They don't em- phasize mass transit and reduce automobile use.In fact,many local governments are taking a hands-off ap- proach."_____________(65),she urges them to change their idle policies and to take strong steps to prevent the harmful effects of climate change on cities. _________(61)
[多选题]共用题干 The iPad1 The iPad is a tablet computer(平板电脑)designed and developed by Apple. It is par-ticularly marketed as a platform for audio and visual media such as books,periodicals(期刊),movies,music,and games,as well as web content. At about 1 .5 pounds(680 grams), its size and weight are between those of most contemporary smartphones and laptop comput-ers.Apple released the iPad in April 2010,and sold 3 million of the devices in 80 days.2 The iPad runs the same operating system as iPod Touch and iPhone. It can run its own applications as well as ones developed for iPhone. Without modification,it will only run pro-grams approved by Apple and distributed via its online store.3 Like iPhone and iPod Touch,the iPad is controlled by a multitouch display一a break from most previous tablet computers, which uses a pressure-triggered stylus(触控笔).The iPad uses a Wi-Fi data connection to browse(浏览)the Internet, load and stream media, and install software. Some models also have a 3G wireless data connection which can connect to GSM 3G data networks. The devices is managed and synchronized(同步)by iTunes on a per-sonal computer via USB cable.4 An iPad has different features and applications one can use to execute different and in-teresting things. There are lots of iPad applications that the owner can use to enhance the way they communicate. Some of these are how to use social networking sites and other online options.One of the most common uses is for e-mail services. iPad applications like Markdown Mail allow the adoption of specific and particular options. They enable the owner to personal-ize their email accounts.5 While the iPad is mostly used by consumers it also has been taken up by business us-ers. Some companies are adopting iPads in their business offices by distributing or making available iPads to employees.Examples of uses in the workplace include lawyers responding to clients,medical professionals accessing health records during patient exams,and manag-ers approving employee requests.A survey by Frost Sullivan shows that iPad usage in work-places is linked to the goals of increased employees productivity,reduced paperwork,and in-creased revenue. iPad applications enable the owner's email accounts to be_______.
[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. _________(61)
[多选题]共用题干 Earth Angels1 Joying Brescia was 8 years old when she noticed that cigarette butts(烟头)were littering her hometown beach in Isle of Palms,South Carolina.When she learned that it takes five years for the remains of a cigarette to disintegrate,she decided to take action. Joying launched a"No Butts on the Beach"campaign.She raised money and awareness about the need to keep the beaches clean.With the help of others,Joying also bought or received donations of gallon-size plastic ice-cream buckets. The buckets were filled with sand,and placed at all public-access areas of the beach.The buckets allowed people to dispose of their cigarettes before hitting the beach.Two years later,Joying says the buckets are full and the beach is nearly free of cigarette debris(残片).2 People who live in or visit Steamboat Springs,Colorado,have Carter Dunham to thank for a new state wildlife refuge that preserves 20 acres of marshland and many species of wildlife.Carter and other students wrote a management plan for the area around the Yampa River.The plan was part of a class project when Carter was a freshman at Steamboat Springs High School.Working with the Colorado Division of Wildlife,Carter and his classmates mapped the area and species of animals living there.They also made decisions about, among other things,where fences and parking areas should be built.3 Barbara Brown and her friends collect oil.It started as a project for their 4H Club after one of the girls noticed her father using motor oil to kill weeds on their farm in Victoria, Texas.They did some research and discovered that oil can contaminate ground water一a real danger in rural areas,where people live off the water on their land.The girls researched ways to recycle oil and worked with a local oil-recycling company on the issue. Now,the"Don't Be Crude"program runs oil-collection sites一tanks that hold up to 460 gallons一where people in the community can dispose of their oil.4 Five years ago,11 -year-old Ryan Hreljac was a little boy with a big dream:for all the people in Africa to have clean drinking water. His dream began in the first grade when he learned that people were dying because they didn't have clean water,and that as little as $70 could build a well, "We really take water for granted,"says Ryan,of Kemptville, Ontario,in Canada. "In other countries,you have to plan for it."Ryan earned the first $70 by doing extra chores(零工),but with the help of others,he has since raised hundreds of thousands of dollars.His efforts led to the start of the Ryan's Well Foundation, which raises money for clean water and health-related services for people in African countries and developing countries. Paragraph 3_________
[多选题]共用题干 Memory Test1 "I am going to give you five techniques that will enable you to remember anything youneed to know at school,"promised lecturer Ian Robinson to a hundred schoolchildren.He slapped his hand down on the table."When I've finished in two hours' time,your work will be far more effective and productive.Anyone not interested, leave now."The entire room sat still.2 Robinson calls himself the Mind Magician(魔术师).He specializes in doing magic tricks that look totally impossible,and then he reveals that they involve nothing more mysteriousthan good old-fashioned trickery(骗术)."I have always been interested in tricks involving memory-being able to reel off(一口气说出)the order of cards in a pack, that sort of thing," he explains.3 Robinson was already lecturing to schools on his magic techniques when it struck him that students might find memory techniques even more valuable."It wasn't a difficult area to move into,as the stuff's all there in books."So he summarized everything to make a two-hour lecture about five techniques.4 "You want to learn a list of a hundred things?A thousand?No problem,"saysRobinson.The scandal is that every child is not taught the techniques from the beginning oftheir school life.The schoolchildren who were watching him thought it was brilliant."I wish I'd been told this earlier,"commented Mark,after Robinson had shown them how to construct"mental journeys".5 Essentially, you visualize(想象)a walk down a street, or a trip round a room,and pick the points where you will put the things you want to remember一the lamppost,the fruit bowl. Then in each location you put a visual representation of your list一phrasal verbs,historical dates,whatever一making them as strange as possible.It is that simple,and it works.6 The reaction of schools has been uniformly enthusiastic."The pupils benefited enormously from lan's presentation,"says Dr Johnston,head of the school where Robinson was speaking."Ideally we should run a regular class in memory techniques so pupils can pick it up gradually." Paragraph 4_______
[多选题]共用题干 Hurricane1 A hurricane(飓风)is a tropical storm with winds that have reached a constant speed of 74 miles per hour. Hurricane winds blow in a large spiral(螺旋)around a relative calm center know as the“eye”.The“eye” is generally 20 to 30 miles wide,and the storm may ex- tend outward 400 miles. As a hurricane nears land,it can bring heavy rains,high winds,and storms(风暴潮).The storm surges and heavy rains can lead to flooding.2 Hurricanes are given a different label,depending on where they occur. If they begin over the North Atlantic Ocean,the Caribbean Sea,the Gulf of Mexico,or the Northeast Pa-cific Ocean,they are called hurricanes.Similar storms that occur in the Northwest Pacific Ocean west of the International Date Line are called typhoon. Near Australia and in the India Ocean, they are referred to as tropical cyclones(龙卷风).3 When a hurricane hits land,it can do great damage through its fierce winds,heavy rains , inland(内陆的)flooding, and huge waves crashing onto the shore. During a hurri-cane,homes,businesses,and public buildings may be damaged or destroyed;road and bridges can be washed away. A powerful hurricane can kill more people and destroy more property than any other natural disaster. Fishermen are at special risk from hurricanes as they may be at sea when a hurricane arrives and not be able to get to a safe harbour if they do not receive adequate warning.4 If a hurricane is coming in your area,the most important thing is to stay calm and find shelter immediately. Go to your safe room. If you do not have one,stay indoors during the hurricane and go to a safer place near the center of your home. Cover yourself with a blanket and be sure to keep away from windows and glass doors,because if the glass breaks it's real-ly dangerous. Do not be fooled if there is a lull(暂停);it could be the eye of the storm-winds will pick up again. Paragraph 2_________
[多选题]共用题干 The iPad1 The iPad is a tablet computer(平板电脑)designed and developed by Apple. It is par-ticularly marketed as a platform for audio and visual media such as books,periodicals(期刊),movies,music,and games,as well as web content. At about 1 .5 pounds(680 grams), its size and weight are between those of most contemporary smartphones and laptop comput-ers.Apple released the iPad in April 2010,and sold 3 million of the devices in 80 days.2 The iPad runs the same operating system as iPod Touch and iPhone. It can run its own applications as well as ones developed for iPhone. Without modification,it will only run pro-grams approved by Apple and distributed via its online store.3 Like iPhone and iPod Touch,the iPad is controlled by a multitouch display一a break from most previous tablet computers, which uses a pressure-triggered stylus(触控笔).The iPad uses a Wi-Fi data connection to browse(浏览)the Internet, load and stream media, and install software. Some models also have a 3G wireless data connection which can connect to GSM 3G data networks. The devices is managed and synchronized(同步)by iTunes on a per-sonal computer via USB cable.4 An iPad has different features and applications one can use to execute different and in-teresting things. There are lots of iPad applications that the owner can use to enhance the way they communicate. Some of these are how to use social networking sites and other online options.One of the most common uses is for e-mail services. iPad applications like Markdown Mail allow the adoption of specific and particular options. They enable the owner to personal-ize their email accounts.5 While the iPad is mostly used by consumers it also has been taken up by business us-ers. Some companies are adopting iPads in their business offices by distributing or making available iPads to employees.Examples of uses in the workplace include lawyers responding to clients,medical professionals accessing health records during patient exams,and manag-ers approving employee requests.A survey by Frost Sullivan shows that iPad usage in work-places is linked to the goals of increased employees productivity,reduced paperwork,and in-creased revenue. Paragraph 4______
[多选题]共用题干 So Many"Earths"The Milky Way(银河)contains billions of Earth-sized planets that could support life.That's the finding of a new study.It draws on data that came from NASA's top planet-hunting telescope.A mechanical failure recently put that Kepler space telescope out of service.Kepler had played a big role in creating a census of planets orbiting some 170,000 stars.Its data have been helping astronomers predict how common planets are in our galaxy.The telescope focused on hunting planets that might have conditions similar to those on Earth.The authors of a study,published in The Proceedings of the National Academy of Sciences,conclude that between 14 and 30 out of every 100 stars,with a mass and temperature similar to the Sun,may host a planet that could support life as we know it.Such a planet would have a diameter at least as large as Earth's,but no more than twice that big.The planet also would have to orbit in a star's habitable zone.That's where the surface temperature would allow any water to exist as a liquid.The new estimate of how many planets might fit these conditions comes from studying more than 42,000 stars and identifying suitable worlds orbiting them.The scientists used those numbers to extrapolate(推算) to the rest of the stars that the telescope could not see.The estimate is rough,the authors admit.If applied to the solar system,it would define as habitable a zone starting as close to the Sun as Venus and running to as far away as Mars.Neither planet is Earthlike (although either might have been in the distant past).Using tighter limits,the researchers estimate that between 4 and 8 out of every 100 sunlike stars could host an Earth-sized world.These are ones that would take 200 to 400 days to complete a yearly orbit.Four out of every 100 sunlike stars doesn't sound like a big number.It would mean,however,that the Milky Way could host more than a billion Earth-sized planets with a chance for life. The planet that could support life might be a little bit smaller than the Earth.
[多选题]共用题干 More Than 8 Hours Sleep Too Much of a Good Thing1 Although the dangers of too little sleep are widely known,new research suggests that people who sleep too much may also suffer the consequences.2 Investigators at the University of California in San Diego found that people who clock up 9 or 10 hours each weeknight appear to have more trouble falling and staying asleep,as well as a number of other sleep problems,than people who sleep 8 hours a night. People who slept only 7 hours each night also said they had more trouble falling asleep and feeling re-freshed after a night's sleep than 8-hour sleepers.3 These findings,which DL Daniel Kripke reported in the journal Psychosomatic Medicine,demonstrate that people who want to get a good night's rest may not need to set aside more than 8 hours a night.He added that“it might be a good idea” for people who sleep more than 8 hours each night to consider reducing the amount of time they spend in bed,but cau-tioned that more research is needed to confirm this.4 Previous studies have shown the potential dangers of chronic shortages of sleep一for instance,one report demonstrated that people who habitually sleep less than 7 hours each night have a higher risk of dying within a fixed period than people who sleep more.5 For the current report,Kripke reviewed the responses of 1,004 adults to sleep ques-tionaires,in which participants indicated how much they slept during the week and whether they experienced any sleep problems. Sleep problems included waking in the middle of the night,arising early in the morning and being unable to fall back to sleep,and having fatigue interfere with day-to-day functioning.6 Kripke found that people who slept between 9 and 10 hours each night were more like-ly to report experiencing each sleep problem than people who slept 8 hours. In an interview, Kripke noted that long sleepers may struggle to get rest at night simply because they spend too much time in bed. As evidence,he added that one way to help insomnia is to spend less time in bed.“It stands to reason that if a person spends too long a time in bed,then they'll spend a higher percentage of time awake.”he said. One survey showed that people who habitually______each night have a higher risk of dying.
[多选题]共用题干 Ecosystem1. The word “ecosystem” is short for ecological(生态的)system. An ecosystem is where living creatures expand within a given area. You can say that an ecosystem is the natural environment where biological organisms(生物)such as plants,animals and humans co-exist in this world. So naturally that includes you and me. Yes,we are all members of an ecosystem!2 .There are different kinds of ecosystems depending on the type of surface or environ-ment. Most are naturally made such as the ocean or lake and the desert or rainforest.Some are man-made or artificial to encourage co-habitation(同居)between living and non-living things in a monitored environment,such as a zoo or garden.3 .Plants make up the biggest group of biological creatures within an ecosystem,and that's because they are the natural food producers for everyone. Plants raised in the earth need air and collect sunlight to help them grow. When they grow,the plants and its fruits or flowers eventually become a source of food to animals,microorganisms(微生物)and even hu- mans,of course. Food is then converted to energy for the rest of us to function,and this hap-pens in a never-ending cycle until the living creatures die and break up back in the earth.4 .Ecosystems are the basis of survival for all living things.We depend on plants and ani-mals for food. In order for us to exist,we need to grow and care about other organisms. We also need to care for the non-living things within our environment like our air and water so we can continue living as a population. Since plants,animals and humans are all of various species(物种),we all play a role in maintaining the ecosystem.5 .To preserve our ecosystems,we should stop using too much energy,which happens when we consume more than our share of resources. Humans should not disturb the natural habitat(栖息地)of plants and animals,and allow them to grow healthily for the cycle to con-tinue. Too many people in a habitat can mean displacement(搬迁): imagine being thrown out of your home because there is no more space for everyone. Worse,overpopulation can also ru- in the environment and cause destruction of existing plants and animals. Plants are essential in an ecosystem because to other living creatures they are______.
[多选题]共用题干 Underground Coal FiresCoal burning deep underground in China,India and Indonesia is threatening the environment and human life , scientists have warned.These large-scale______(51)blazes(火焰)cause the ground temperature to heat up and kill surrounding vegetation,produce greenhouse gases and can______(52) ignite(点燃)forest fires , a group of scientists told the annual meeting of the American Association for theAdvancement of Science in Denver.The resulting______(53)of poisonous elements like mercury can also pollute local water sources and soils,they warned."Coal fires are a global disaster,"said Associate Professor Glenn Stracher of East Georgia College inSwainsboro,USA.But______(54)few people know about them.Coal can heat up on its own,and eventually catch fire and bum,if there is a continuous oxygen supply.The heat produced is not caused to______(55)and under the right combinations of sunlight and oxygen,can trigger spontaneous(自发的)catching fire and buming.This can occur underground , in coal stockpiles, abandoned mines or even as coal is transported.______(56)fires in China consume up to 200 million tons of coal per year,delegates were told.In______(57),the U.S.economy consumes about one billion tons of coal annually,said Stracher,______(58)analysis of the likely impact of coal fires has been accepted for publication in the International Journal of Coal Ecology.______(59)underway,coal fires can bum for decades,even centuries.In the process,they release large______(60)of greenhouse gases,poisonous fumes and black particles into the atmosphere.The members of the panel discussed the______(61)these fires may be having on global and regional climate change,and agreed that the underground nature of the fires makes them difficult to______(62).Ultimately,the remote sensing and other techniques should allow scientists to______(63)how much carbon dioxide these fires are emitting(释放).One suggested______(64)of containing the fires was presented by Gary Colaizzi,of the engineering firm Goodson,which has developed a heat-resistant grout(灌浆),which is designed to be pumped into the coal fire to______(65)the oxygen supply. _________51
[多选题]共用题干 Hurricane1 A hurricane(飓风)is a tropical storm with winds that have reached a constant speed of 74 miles per hour. Hurricane winds blow in a large spiral(螺旋)around a relative calm center know as the“eye”.The“eye” is generally 20 to 30 miles wide,and the storm may ex- tend outward 400 miles. As a hurricane nears land,it can bring heavy rains,high winds,and storms(风暴潮).The storm surges and heavy rains can lead to flooding.2 Hurricanes are given a different label,depending on where they occur. If they begin over the North Atlantic Ocean,the Caribbean Sea,the Gulf of Mexico,or the Northeast Pa-cific Ocean,they are called hurricanes.Similar storms that occur in the Northwest Pacific Ocean west of the International Date Line are called typhoon. Near Australia and in the India Ocean, they are referred to as tropical cyclones(龙卷风).3 When a hurricane hits land,it can do great damage through its fierce winds,heavy rains , inland(内陆的)flooding, and huge waves crashing onto the shore. During a hurri-cane,homes,businesses,and public buildings may be damaged or destroyed;road and bridges can be washed away. A powerful hurricane can kill more people and destroy more property than any other natural disaster. Fishermen are at special risk from hurricanes as they may be at sea when a hurricane arrives and not be able to get to a safe harbour if they do not receive adequate warning.4 If a hurricane is coming in your area,the most important thing is to stay calm and find shelter immediately. Go to your safe room. If you do not have one,stay indoors during the hurricane and go to a safer place near the center of your home. Cover yourself with a blanket and be sure to keep away from windows and glass doors,because if the glass breaks it's real-ly dangerous. Do not be fooled if there is a lull(暂停);it could be the eye of the storm-winds will pick up again. Paragraph 4_________
[多选题]共用题干 第二篇Students Learn Better with Touchscreen DesksObserve the criticisms of nearly any major public education system in the world,and a few of the many complaints are more or less universal.Technology moves faster than the education system.Teachers must teach at the pace of the slowest student rather than the fastest. And一particularly in the United States一 school children as a group don't care much for,or excel(擅长)at,mathemnatics. So it's heartening to learn that a new kind of"classroom of the future"shows promise at easing some of these problems,starting with that fundamental piece of classroom furniture:the desk.A UK study involving roughly 400 students,mostly aged 8一10 years,and a new generation of multis-touch,multi-user,computerized desktop surfaces is showing that over the last three years the technology has appreciably boosted students'math skills compared with peers learning the same material via the con- ventional paper-and-pencil method.How?Through collaboration,mostly,as well as by giving teachers better tools by which to micromanage individual students who need some extra instruction while allowing the rest of the class to continue moving forward.Traditional instruction still shows respectable efficacy(效力)at increasing students'fluency in mathe- matics,essentially through memorization and practice一dull,repetitive practice.But the researchers have con-cluded that these new touchscreen desks boost both fluency and flexibility一the critical thinking skills that al- low students to solve complex problems not simply through knowing formulas and devices,but by being able to figure out what the real problem is and the most effective means of stripping it down and solving it.One reason for this,the researchers say,is the multi-touch aspect of the technology.Students working in the next-gen classroom can work together at the same tabletop,each of them contributing and engaging with the problem as part of a group.Known as SynergyNet,the software uses computer vision systems that see in the infrared(红外线的)spectrum to distinguish between different touches on different parts of the surface, allowing students to access and use tools on the screen,move objects and visual aids around on their desk- tops,and otherwise physically interact with the numbers and information on their screens.By using these screens collaboratively,the researchers say,the students are to some extent teaching themselves as those with a stronger grasp on difficult concepts pull other students forward along with them. What happens when students are using the desktop of the new tech?
[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. _________(65)
[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. _________(58)
[多选题]共用题干 Learn about Light1 .Ancient civilizations were amazed by the existence of light for thousands of years. The Greek philosophers believed that light was made up of countless,tiny particles that enter the human eye and create what we call vision. However,Empedocles and a Dutch scientist named Christian Huygens believed that light was like a wave. According to them,light spread out and travelled like a straight line. This theory was accepted during the 19th century.2 .In 1905,Albert Einstein published a research paper in which he explained what is re-ferred to as the photoelectric effect. This theory explains that particles make up light.The particles Einstein was referring to are weightless bundles(束)of electromagnetic(电磁)energy called photons(光子).Today,scientists agree that light has a dual(二重)nature一it is part particle and part wave. It is a form of energy that allows us to see things around us.3 .Things that give off light are known as sources of light. During the day,the primary source of light is the sun. Other sources of light include stars,flames,flashlights,street lamps and glowing gases in glass tube.4 .When we draw the way light travels we always use straight lines. This is because nor-mally light rays travel in a straight line. However,there are some instances that can change the path and even the nature of light. They are reflection,absorption,interference(干扰), etc.5 .Physicists have attempted to measure the speed of light since the early times. In 1849, Hippolyte Fizeau conducted an experiment by directing a beam of light to a mirror located kilometers away and placed a rotating cogwheel(旋转齿轮)between the beam and the mirror. From the rate of rotation of the wheel,number of wheel's teeth and distance of the mirror,he was able to calculate that the speed of light is 313 million meters per second. In a vacuum(真空),however,the speed of light is 299,792,458 meters per second. This is about a million times faster than the speed of an airplane. Paragraph 3______
[多选题]共用题干 Climate Change Poses Major Risks for Unprepared CitiesA new examination of urban policies has been carried out recently by Patricia Romero Lankao. She is a so- ciologist specializing in climate change and_____________(51) development. She warns that many of the world'5 fast-growing urban areas,especially in developing countries,will likely suffer from the_____________(52)of changing climate. Her work also concludes that most cities are failing to_____________(53)emissions of carbon dioxide and other greenhouse gases. These gases are known to affect the atmosphere."Climate change is a deeply local issue and poses profound_____________ (54) to the growing cities of the world,"says Romero Lankao. "But too few cities are developing effective strategies to protect their residents."Cities are_____________(55)sources of greenhouse gases.And urban populations are likely to be among those most severely affected by future climate change.Lankao's findings highlight ways in which city-resi- dents are particularly vulnerable,and suggest policy interventions that could offer immediate and longer-term ____________ (56).The locations and dense construction patterns of cities often place their populations at greater _____________(57)for natural disasters.Potential threats associated with climate include storm surges and pro- longed hot weather. Storm surges can flood coastal areas and prolonged hot weather can heat_____________(58) paved cities more than surrounding areas. The impacts of such natural events can be more_____________(59)in an urban environment. For example,a prolonged heat wave can increase existing levels of air pollution,causing widespread health problems.Poorer neighborhoods that may_____________(60)basic facilities such as drinking water or a dependable network of roads,are especially vulnerable to natural disasters.Many residents in poorer countries live in substandard housing_____________(61)access to reliable drinking water,roads and basic services.Local governments,therefore,should take measures to_____________(62)their residents."Unfortunately, they tend to move towards rhetoric_____________(63)meaningful responses,"Romero Lankao writes,"They don't impose construction standards that could reduce heating and air conditioning_____________(64).They don't em- phasize mass transit and reduce automobile use.In fact,many local governments are taking a hands-off ap- proach."_____________(65),she urges them to change their idle policies and to take strong steps to prevent the harmful effects of climate change on cities. _________(57)
[多选题]共用题干 Memory Test1 "I am going to give you five techniques that will enable you to remember anything youneed to know at school,"promised lecturer Ian Robinson to a hundred schoolchildren.He slapped his hand down on the table."When I've finished in two hours' time,your work will be far more effective and productive.Anyone not interested,leave now."The entire room sat still.2 Robinson calls himself the Mind Magician(魔术师).He specializes in doing magic tricks that look totally impossible,and then he reveals that they involve nothing more mysteriousthan good old-fashioned trickery(骗术)."I have always been interested in tricks involving memory-being able to reel off(一口气说出)the order of cards in a pack, that sort of thing," he explains.3 Robinson was already lecturing to schools on his magic techniques when it struck him that students might find memory techniques even more valuable."It wasn't a difficult area to move into,as the stuff's all there in books."So he summarized everything to make a two-hour lecture about five techniques.4 "You want to learn a list of a hundred things?A.thousand?No problem,"says Robinson.The scandal is that every child is not taught the techniques from the beginning oftheir school life.The schoolchildren who were watching him thought it was brilliant."I wish I'd been told this earlier,"commented Mark,after Robinson had shown them how to construct"mental journeys".5 Essentially , you visualize(想象)a walk down a street, or a trip round a room,and pick the points where you will put the things you want to remember一the lamppost,the fruit bowl. Then in each location you put a visual representation of your list一phrasal verbs,historical dates,whatever一making them as strange as possible.It is that simple,and it works.6 The reaction of schools has been uniformly enthusiastic."The pupils benefitedenormously from Ian's presentation,"says Dr. Johnston,head of the school where Robinson was speaking. "Ideally we should run a regular class in memory techniques so pupils can pick it up gradually." Paragraph 4________
[多选题]共用题干 Climate Change Poses Major Risks for Unprepared CitiesA new examination of urban policies has been carried out recently by Patricia Romero Lankao. She is a so- ciologist specializing in climate change and_____________(51) development. She warns that many of the world'5 fast-growing urban areas,especially in developing countries,will likely suffer from the_____________(52)of changing climate. Her work also concludes that most cities are failing to_____________(53)emissions of carbon dioxide and other greenhouse gases. These gases are known to affect the atmosphere."Climate change is a deeply local issue and poses profound_____________ (54) to the growing cities of the world,"says Romero Lankao. "But too few cities are developing effective strategies to protect their residents."Cities are_____________(55)sources of greenhouse gases.And urban populations are likely to be among those most severely affected by future climate change.Lankao's findings highlight ways in which city-resi- dents are particularly vulnerable,and suggest policy interventions that could offer immediate and longer-term ____________ (56).The locations and dense construction patterns of cities often place their populations at greater _____________(57)for natural disasters.Potential threats associated with climate include storm surges and pro- longed hot weather. Storm surges can flood coastal areas and prolonged hot weather can heat_____________(58) paved cities more than surrounding areas. The impacts of such natural events can be more_____________(59)in an urban environment. For example,a prolonged heat wave can increase existing levels of air pollution,causing widespread health problems.Poorer neighborhoods that may_____________(60)basic facilities such as drinking water or a dependable network of roads,are especially vulnerable to natural disasters.Many residents in poorer countries live in substandard housing_____________(61)access to reliable drinking water,roads and basic services.Local governments,therefore,should take measures to_____________(62)their residents."Unfortunately, they tend to move towards rhetoric_____________(63)meaningful responses,"Romero Lankao writes,"They don't impose construction standards that could reduce heating and air conditioning_____________(64).They don't em- phasize mass transit and reduce automobile use.In fact,many local governments are taking a hands-off ap- proach."_____________(65),she urges them to change their idle policies and to take strong steps to prevent the harmful effects of climate change on cities. _________(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. It is indicated that materials stronger than natural silk can be expected in the future.
[多选题]共用题干 Learn about Light1 .Ancient civilizations were amazed by the existence of light for thousands of years. The Greek philosophers believed that light was made up of countless,tiny particles that enter the human eye and create what we call vision. However,Empedocles and a Dutch scientist named Christian Huygens believed that light was like a wave. According to them,light spread out and travelled like a straight line. This theory was accepted during the 19th century.2 .In 1905,Albert Einstein published a research paper in which he explained what is re-ferred to as the photoelectric effect. This theory explains that particles make up light.The particles Einstein was referring to are weightless bundles(束)of electromagnetic(电磁)energy called photons(光子).Today,scientists agree that light has a dual(二重)nature一it is part particle and part wave. It is a form of energy that allows us to see things around us.3 .Things that give off light are known as sources of light. During the day,the primary source of light is the sun. Other sources of light include stars,flames,flashlights,street lamps and glowing gases in glass tube.4 .When we draw the way light travels we always use straight lines. This is because nor-mally light rays travel in a straight line. However,there are some instances that can change the path and even the nature of light. They are reflection,absorption,interference(干扰), etc.5 .Physicists have attempted to measure the speed of light since the early times. In 1849, Hippolyte Fizeau conducted an experiment by directing a beam of light to a mirror located kilometers away and placed a rotating cogwheel(旋转齿轮)between the beam and the mirror. From the rate of rotation of the wheel,number of wheel's teeth and distance of the mirror,he was able to calculate that the speed of light is 313 million meters per second. In a vacuum(真空),however,the speed of light is 299,792,458 meters per second. This is about a million times faster than the speed of an airplane. Stars,flames,flashlights are some examples of______.
[多选题]共用题干 Why India Needs Its Dying VulturesThe vultures(秃鹰)in question may look ugly and threatening , but the sudden sharp decline in three species of India'S vultures is producing alarm rather than celebration,and it presents the world with a new kind of environmental problem.The dramatic__________(51)in vulture numbers is causing widespread disruption to people living in the__________(52)areas as the birds.It is also causing serious public health problems__________(53)the Indian sub-continent.While their reputation and appearance may be unpleasant to many Indians,vultures have___________(54) played a very important role in keeping towns and villages all over India___________(55).It is because they feed on dead cows.In India,cows are sacred animals and are___________(56) left in the open when they die in thousands upon thousands every year.The disappearance of the vultures has___________(57)an explosion in the numbers of wild dogs feeding on the remains of these___________(58)animals. There are fears that rabies(狂犬症)may increase as a result. And this terrifying disease may ultimately(最终)affect humans in the region,___________(59)wilddogs are its main carriers.Rabies could also spread to other animal species, __________(60)an even greater problem in the future.The need for action is___________(61),so an emergency project has been launched to find a solution to this serious vulture problem?Scientists are trying to___________(62)the disease causing the birds' deaths and,if possible,develop a cure.Large-scale vulture___________(63)were first noticed at the end of the l980s in India. A population survey at that time showed that the three species of vultures had declined___________(64)over 90 percent. All three species are now listed as"critically endangered".As most vultures lay only single eggs and ___________(65)about five years to reach maturity,reversing their population decline will be a long and dif- ficult exercise. _________(57)
[多选题]共用题干 Ecosystem1. The word “ecosystem” is short for ecological(生态的)system. An ecosystem is where living creatures expand within a given area. You can say that an ecosystem is the natural environment where biological organisms(生物)such as plants,animals and humans co-exist in this world. So naturally that includes you and me. Yes,we are all members of an ecosystem!2 .There are different kinds of ecosystems depending on the type of surface or environ-ment. Most are naturally made such as the ocean or lake and the desert or rainforest.Some are man-made or artificial to encourage co-habitation(同居)between living and non-living things in a monitored environment,such as a zoo or garden.3 .Plants make up the biggest group of biological creatures within an ecosystem,and that's because they are the natural food producers for everyone. Plants raised in the earth need air and collect sunlight to help them grow. When they grow,the plants and its fruits or flowers eventually become a source of food to animals,microorganisms(微生物)and even hu- mans,of course. Food is then converted to energy for the rest of us to function,and this hap-pens in a never-ending cycle until the living creatures die and break up back in the earth.4 .Ecosystems are the basis of survival for all living things.We depend on plants and ani-mals for food. In order for us to exist,we need to grow and care about other organisms. We also need to care for the non-living things within our environment like our air and water so we can continue living as a population. Since plants,animals and humans are all of various species(物种),we all play a role in maintaining the ecosystem.5 .To preserve our ecosystems,we should stop using too much energy,which happens when we consume more than our share of resources. Humans should not disturb the natural habitat(栖息地)of plants and animals,and allow them to grow healthily for the cycle to con-tinue. Too many people in a habitat can mean displacement(搬迁): imagine being thrown out of your home because there is no more space for everyone. Worse,overpopulation can also ru- in the environment and cause destruction of existing plants and animals. In an ecosystem,plants,animals and humans live together in______.
[多选题]共用题干 Ford1 Ford's great strength was the manufacturing process一not invention.Long before he started a car company,he was a worker,known for picking up pieces of metal and wire and turning them into machines.He started putting cars together in 1891.Although it was by no means the first popular automobile,the Model T showed the world just how creative Ford was at combining technology and market.2 The company's assembly line alone threw America's Industrial Revolution into overdrive (高速运转).Instead of having workers put together the entire car , Ford's friends , who were great toolmakers from Scotland,organized teams that added parts to each Model T as it moved down a line. By the time Ford's Highland Park plant was humming(嗡嗡作响) along in 1914,the world's first automatic conveyor belt could turn out a car every 93 minutes.3 The same year Henry Ford shocked the world with the$5-a-day minimum wage scheme,the greatest contribution he had ever made. The average wage in the auto industry thenwas $2.34 for a 9-hour shift. Ford not only doubled that,he also took an hour off the workday.In those years it was unthinkable that a man could be paid that much for doing something that didn't involve an awful lot of training or education.The Wall Street Journal called the plan"an economic crime",and critics everywhere laughed at Ford.4 But as the wage increased later to daily$10,it proved a critical component of Ford's dream to make the automobile accessible(可及的)to all. The critics were too stupid to understand that because Ford had lowered his costs per car,the higher wages didn't matter一 except for making it possible for more people to buy cars. Paragraph 4_______
[多选题]共用题干 The iPad1 The iPad is a tablet computer(平板电脑)designed and developed by Apple. It is par-ticularly marketed as a platform for audio and visual media such as books,periodicals(期刊),movies,music,and games,as well as web content. At about 1 .5 pounds(680 grams), its size and weight are between those of most contemporary smartphones and laptop comput-ers.Apple released the iPad in April 2010,and sold 3 million of the devices in 80 days.2 The iPad runs the same operating system as iPod Touch and iPhone. It can run its own applications as well as ones developed for iPhone. Without modification,it will only run pro-grams approved by Apple and distributed via its online store.3 Like iPhone and iPod Touch,the iPad is controlled by a multitouch display一a break from most previous tablet computers, which uses a pressure-triggered stylus(触控笔).The iPad uses a Wi-Fi data connection to browse(浏览)the Internet, load and stream media, and install software. Some models also have a 3G wireless data connection which can connect to GSM 3G data networks. The devices is managed and synchronized(同步)by iTunes on a per-sonal computer via USB cable.4 An iPad has different features and applications one can use to execute different and in-teresting things. There are lots of iPad applications that the owner can use to enhance the way they communicate. Some of these are how to use social networking sites and other online options.One of the most common uses is for e-mail services. iPad applications like Markdown Mail allow the adoption of specific and particular options. They enable the owner to personal-ize their email accounts.5 While the iPad is mostly used by consumers it also has been taken up by business us-ers. Some companies are adopting iPads in their business offices by distributing or making available iPads to employees.Examples of uses in the workplace include lawyers responding to clients,medical professionals accessing health records during patient exams,and manag-ers approving employee requests.A survey by Frost Sullivan shows that iPad usage in work-places is linked to the goals of increased employees productivity,reduced paperwork,and in-creased revenue. Paragraph 4______
[多选题]共用题干 The iPad1 The iPad is a tablet computer(平板电脑)designed and developed by Apple. It is par-ticularly marketed as a platform for audio and visual media such as books,periodicals(期刊),movies,music,and games,as well as web content. At about 1 .5 pounds(680 grams), its size and weight are between those of most contemporary smartphones and laptop comput-ers.Apple released the iPad in April 2010,and sold 3 million of the devices in 80 days.2 The iPad runs the same operating system as iPod Touch and iPhone. It can run its own applications as well as ones developed for iPhone. Without modification,it will only run pro-grams approved by Apple and distributed via its online store.3 Like iPhone and iPod Touch,the iPad is controlled by a multitouch display一a break from most previous tablet computers, which uses a pressure-triggered stylus(触控笔).The iPad uses a Wi-Fi data connection to browse(浏览)the Internet, load and stream media, and install software. Some models also have a 3G wireless data connection which can connect to GSM 3G data networks. The devices is managed and synchronized(同步)by iTunes on a per-sonal computer via USB cable.4 An iPad has different features and applications one can use to execute different and in-teresting things. There are lots of iPad applications that the owner can use to enhance the way they communicate. Some of these are how to use social networking sites and other online options.One of the most common uses is for e-mail services. iPad applications like Markdown Mail allow the adoption of specific and particular options. They enable the owner to personal-ize their email accounts.5 While the iPad is mostly used by consumers it also has been taken up by business us-ers. Some companies are adopting iPads in their business offices by distributing or making available iPads to employees.Examples of uses in the workplace include lawyers responding to clients,medical professionals accessing health records during patient exams,and manag-ers approving employee requests.A survey by Frost Sullivan shows that iPad usage in work-places is linked to the goals of increased employees productivity,reduced paperwork,and in-creased revenue. iPad usage in offices enables employee productivity to be_______.
[多选题]共用题干 Early Ideas about the Universe1 Early man got his ideas about the universe by looking at the stars as you do.He observed carefully,and learned many things about the sun,the moon,and the stars.2 Suppose you were asked to collect evidence about the sun as early man did.You might go out morning after morning and see it come up in the east.Even on cloudy mornings,youwould observe that the darkness goes away and the world becomes light.You might not see the sun but would be sure it is there,because you notice that the earth warms up.As you continued,the sun climbs higher in the sky each day during part of the year. It stays in the sky longer. The earth gets warmer. Things begin to grow. It is spring and then summer.3 After a while the sun stays in the sky for shorter and shorter periods.Many plants begin to die.Leaves fall.Winter comes.Year after year this is repeated and you cannot tell exactly why it happens.But you realize that the sun seems to make the difference. Primitive(原始的)man felt that since the sun was so powerful it must be a god. It may seem silly to us now to worship(崇拜)a sun-god, but primitive man was right about the importance of the sun to life on earth.4 You have been told that the world is round.But suppose no one had ever taught you that the world was like a huge ball.Would you have ever thought of it yourself?You cannot see the curve(曲线)of the earth at once. You would have no idea of how big it was. That's why early man believed that the earth was small and flat.Such ideas appeared from the evidence they had.5 If you watch the stars night after night,you will see them rise and set.As you look at the sky,it is not difficult to imagine that you are in the center of a vast collection of twinkling(闪烁)lights. Some early astronomers(天文学家)believed the sky was a crystal shell or series of crystal shells,one inside the other. They believed this because that is what the night sky looked like.For many centuries,men believed that the earth was the center of the universe and that the sun,the moon,and the stars circled around it. Paragraph 3_________