题目内容
根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
It’s such a common event that you probably never asked yourself why you sleep. ___1____ In fact, for sleep researchers, it’s one of the biggest unanswered questions in the field.
Stop and think about it for a second. Why should we sleep? ____2_____ But we sleep every night, even when we have had plenty of rest. There are,no doubt,several different answers to this question, but let’s just consider one general purpose of sleep: ____3_____ Human beings are creatures that are normally active during daylight hours, when our senses function most effectively. ____4_____ We can’t see objects well, our color vision is entirely lost, and we don’t have the smelling or hearing sharpness of other animals. So it actually does make sense to have us stay where we are during the dangerous period when night-waking animals are walking here and there. And one sure way to make sure we don’t fall down everywhere and get lost or eaten is to have us not move for seven or eight hours, rising again only when the light is back and our survival chances are better.
It’s not the only reason we sleep. ____5____Perhaps even the most important one.
A. Is it because we get tired?
B. Should that put human beings in a terrible situation?
C. But from a scientific point of view, this is far from an ordinary matter.
D. But in terms of evolution, it may have been one of the first reasons.
E. Furthermore, if you were designing an animal, would you have it come into long periods of unconsciousness every twenty-four hours?
F. Sleep as a survival approach.
G. At night, humans do rather poorly.
C
A
F
G
D
【解析】略
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第二节(共5小题;每小题2分,满分10分)
根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
In 1990 a report was published about what the earth might be like 20 years from then on. 71 According to the report,the picture of the earth in the year 2010 is not a pleasant one. 72 The population could be as large as 6300 million,almost 2150 million more than in 1985.More people would move into cities ,especially cities in developing countries.Cities like Cairo and Jakarta probably would each have 15 million by then.
73 Farmers will grow 90% more food than they did in 1985,but most of the increase would be in countries that already produce enough food for their people. 74 Poor farming ways are destroying large areas of crop land,changing farms into deserts.More farmland is lost as cities become larger and more houses are built.Air pollution will get worse as industrial countries burn more coal and oil.Many of the world's forests could disappear as more and more trees are cut down.Energy will continue to be a serious problem. 75 They only workde out the situation that exists today.By changing the situation,by settling the problems,the picture can be changed.There is still time for the nations of the world to work out a plan of action.But they warned that waiting too long to make de cisions would greatly reduce the chances of success.
A.Food production will increase,but not enough to feed all the people. |
B.The report was a result of a three - year study. |
C.Later on,more reports came out one by one. |
D.The world will be more crowded because the population will continue to grow. |
E.Experts believe enough food will be produced in developing countries very soon.
F.The experts say their picture of the earth for the year 2010 may be wrong.
G.Little increase is expected in South Asia,Africa and the Middle East.