听力原文： Scientists have observed that plants the...

第1题

听力原文：It was not until one hundred and fifty years ago that scientists learned about th

听力原文： It was not until one hundred and fifty years ago that scientists learned about the existence of dinosaurs. Thanks to an English doctor and his wife, the door was opened to this zoological study. Reasoning that these animals' tremendous size must have made them terrible creatures, scientists combined two Greek words, deimos, meaning terrible, and sauros, meaning lizards, to form. the word dinosaur.

After many years of study, they determined that these beasts roamed the earth for millions of years, and ceased to exist some sixty million years ago.

Unbelievable as it may seem, not all dinosaurs were carnivorous, that is, meat eating. Many were herbivorous, or vegetarians.

By reassembling the bones found at digging sites, scientists have been able to reconstruct the skeletons and learn great deal about the dinosaur's living conditions. They have learned that dinosaurs inhabited not only the land, but also the water and sky.

(33)

A．Beasts.

B．Herbivorous.

C．Carnivorous.

D．Dinosaurs.

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第2题

听力原文：Demand for specialized technical skills has long exceeded the supply of native-bo

rn workers with advanced degrees, and scientists and engineers from other countries fill this gap.

(25)

A．Supply of native-born scientists and engineers exceeded the demand.

B．Scientists and engineers in other countries have specialized technical skills.

C．Foreign scientists and engineers help to meet the domestic demand.

D．Supply of native-born scientists and engineers can meet the demand.

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第3题

听力原文：With the development of science, scientists have discovered more about the world.

听力原文： With the development of science, scientists have discovered more about the world. Scientists say world coastal areas must prepare now for a rise in sea levels. No matter what action is taken, scientists say there are already enough greenhouse gases in the atmosphere to cause a major warning. As a result, scientists and government officials are focusing on how society might adapt to rising sea levels, changing agricultural zones, changing climates and other problems.

Already, state and local governments along the coast of the United States are starting to plan for a possible longterm rise in the sea level, and a few have taken action to cope with it. Agricultural researchers are developing heat-resistant and draught-resistant crops that might replace traditional crops if the climate changes. How long it will take for maximum warming to be reached is uncertain because the oceans slow such warming. Most scientists expect the maximum warming to take place by the second half of this century.

If levels of greenhouse gases in the atmosphere double, sea levels will rise; estimates of the average rise are from 1.5 feet to 6.5 feet. Some leading experts expect a rise of I meter, a little more than three feet.

(33)

A．Pollution of coastal areas.

B．Rise in sea levels.

C．Exhaustion of sea resources.

D．Earthquakes and volcanoes.

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第4题

听力原文：Science fiction writers have often imagined human beings going to live on Mars. B

听力原文： Science fiction writers have often imagined human beings going to live on Mars. But these days scientists are taking the idea seriously. It has a great deal to recommend it since it might solve the problem of overcrowding on the earth, but obviously it would not be worth making the effort unless people could live there naturally. If the were like that of Earth, this might be possible. But m fact, it s mostly carbon dioxide(CO2). Apart from that, there are other problems to be overcome. For example, the temperature would have to be raised from 60~C below zero to 15~C above it. Scientists who study Mars have laid down the program that they can follow. To begin with, they will have to find out whether life has ever existed on planet Mars in the past. Secondly, they will have to make a reliable map of its surface, and finally they will have to make a list of the gases. Above all, they will have to discover how much nitrogen it possesses, since nitrogen is four-fifths of the air we breathe. They're surprisingly optimistic about raising the temperature on Mars and believe it could be done in 200 years. It would take a bit longer, though, to transform. the atmosphere so that human beings could live there. Scientists estimate that this will take 100,000years.

(33)

A．Because people might have to migrate there someday.

B．Because it is very much like the earth.

C．Because it is easier to explore than other planets.

D．Because its atmosphere is different from that of the earth.

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第5题

听力原文：Science fiction writers have often imagined human beings going to live on Mars. B

听力原文： Science fiction writers have often imagined human beings going to live on Mars. But these days, scientists are taking the idea seriously. It has a great deal to recommend it, since it might solve the problem of overcrowding on the earth. But obviously, it would not be worth making the effort unless people could live there naturally. If the atmosphere were like that of the earth, this might be possible. But in fact it is mostly carbon dioxide. Apart from that, there are other problems to be overcome. For example, the temperature Would have to be raised from 60 degrees below zero to 15 degrees above it. Scientists who study Mars have laid down the program that they can follow. To begin with, they will have to find out whether life has ever existed on the planet of Mars in the past. Secondly, they will have to make a reliable map of its surface. And finally, they will have to make a list of the gases. Above all, they will have to discover how much nitrogen it possesses, since nitrogen is four fifths of the air we breathe. They are surprisingly optimistic about raising the temperature on Mars and believe it could be done in two hundred years. It will take a bit longer, though, to transform. the atmosphere so that human beings, could live there. Scientists estimate that this will take one hundred thousand years.

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A．Because people might have to migrate there someday.

B．Because it is very much like the earth.

C．Because it is easier to explore than other planets.

D．Because its atmosphere is different from that of the earth.

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第6题

听力原文：Scientists say they can tell what air and sea conditions were like hundreds of th

听力原文： Scientists say they can tell what air and sea conditions were like hundreds of thousands of years ago. They say pieces of ice taken from Greenland provide such information.

Scientists took the ice from more than one-and-a-half mile deep in huge masses of ice that float on the sea. That is the deepest scientists ever have drilled for ice. The ice represents 25,000 years of history. It provides one of the clearest records of ancient weather.

European and American scientific teams have been studying ice from the same area to confirm each other's findings. The scientists examine the ice that was formed each year. They measure the oxygen and carbon dioxide in the ice. These measurements tell about the year's temperature.

From these measurements, the scientific teams say that the past 10,000 years is the only period during which the weather has not changed very much. Before that time, they believe very large, sudden changes in the weather were common. The ice appears to show that at some periods, Earth's weather changed from very hot to very cold in only ten years.

According to the news, the ice from Greenland provides information about

A．oxygen.

B．ancient weather.

C．carbon dioxide.

D．temperature.

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第7题

听力原文：No one knows exactly why we sleep. But scientists have learned a lot about how we

听力原文： No one knows exactly why we sleep. But scientists have learned a lot about how we sleep, From sleep experiments, scientists have learned that there are four different stages of sleep.

When you first fall asleep, your heart starts to beat more slowly and your breathing slows down. If something wakes you, you might not think that you had been asleep. Some people call this kind of sleep dozing. Scientists call it Stage One sleep. Next, if you are not awakened, you drift into a deeper sleep. Your pulse and breathing become even slower than they were during Stage One sleep. But you can still be awakened quite easily. If you take a cat nap, you probably will not get any further than this stage of sleep, which is called Stage Two.

If you sleep longer than about twenty minutes, you go into the third stage of sleep. Your body is very relaxed. It would take a loud noise to wake you up.

You have probably heard of people who walk in their sleep. No one knows what makes people sleepwalk. But a person can sleepwalk only during Stage Four. This is the deepest kind of sleep. If someone wakes you up during stage four, you might feel very confused. It might take you a few minutes to get used to being awake.

(36)

A．Reasons for People's Sleeping.

B．Four Stages of Sleep.

C．Reasons for sleepwalking.

D．A Sleep Experiment.

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第8题

听力原文：Scientists have observed that plants themselves produce many poisonous chemicals

听力原文： Scientists have observed that plants themselves produce many poisonous chemicals for defence against insects. But insects have developed ways of dealing with them and, in fact, have been eating plants for about 250 million years. Now insects are using these same mechanisms to deal with man-made poisons--insecticides. This is why resistance of insects to insecticides has developed so rapidly.

What should be done？ Scientists studying the problem suggest that farmers use less insecticides. At the moment, farmers regularly spray crops as a precaution against problems that are caused by large numbers of pests. They should, instead, spray only where pests have actually been seen. Secondly, farmers could use a combination of two or three insecticides at once. To survive, the insects would need to become resistant to two or more poisons at the same time.

The most surprising suggestion, perhaps, is that, at certain times of the year, farmers should actually try to attract new insects onto the crops they are trying to protect. The new insects will mate with those which survived from a certain kind of insecticide and will lessen the latter's resistance to it.

Scientists hope that these and other measures will postpone the day when farmers and scientists will have to stand by while new super-bugs which may be resistant to all our poisons invade our farms and eat our crops.

(33)

A．Plants can produce some poisonous chemical for defence against insects.

B．Insects have been eating plants for many million years.

C．Insects have developed ways of dealing with poisonous chemicals produced by plants themselves.

D．Insects have already developed some resistance to man-made poisons.

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第9题

听力原文：Why don't birds got lost on their long migratory flights？ Scientists have puzzled

听力原文： Why don't birds got lost on their long migratory flights？ Scientists have puzzled over this question for many years. Now they're beginning to fill in the blanks.

Not long ago, experiments showed that birds rely on the sun to guide them during daylight hours. But what about birds that fly mainly by night？ Tests with artificial stars have proved conclusively that certain night-flying birds are able to follow the stars in their long-distance flights.

One such bird—a warbler—had spent its lifetime in a cage and had never flown under a natural sky. Yet it showed an inborn ability to use the stars for guidance. The bird's cage was placed under an artificial star-filled sky at migration time. The bird tried to fly in the same direction as that taken by his outdoor cousins. Any change in the position of the make-believe stars caused a change in the direction of his flight.

Scientists think that warblers, when flying in daylight, use the sun for guidance. But the stars are apparently their principal means of navigation. What do they do when the stars are hidden by clouds？ Apparently, they find their way by such landmarks as mountain ranges, coast lines, and rivet courses. But when it's too dark to see these, the warblers circle helplessly, unable to get their bearings.

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A．Birds have to be taught to navigate.

B．A bird that has been caged will not.

C．Some birds cannot fly at night.

D．Some birds seem instinctively to follow the stars when flying at night.

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第10题

听力原文：A few months ago, [32] a team of interviewers were sent to schools to find out wh

听力原文： A few months ago, [32] a team of interviewers were sent to schools to find out why children are prejudiced against science. Their answer provided this surprising picture of a typical scientist: they thought [33] a scientist is a rather dull person who spends all day working in a laboratory, wearing a white coat and making things that smell bad. They thought that scientists usually aren't very interesting and don't talk about anything but science. They don't play games well and they aren't attractive to the opposite sex. They also did not realize that women are as capable of becoming scientists as men.

On the other hand, [34] an art graduate is seen as a much livelier person. Arts graduates are thought to have a better sense of humor, to be interested in sports and pop music and to be considered attractive. When you understand these misconceptions which children have, it is only logical that most of them want to study arts rather than science.

(33)

A．Scientists.

B．Art graduates.

C．Children.

D．Women.

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