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题型:阅读选择 题类:压轴题 难易度:容易

Today there are 6.4 billion people on the earth. By the year 2050 there may be 12.5 billion . There are a lot of people to feed. We need more  and more food.
One way to produce more food is growing stronger plants. For thousands of years, farmers have made plants better. Every season, they pick the best plants for the next season. It works very slowly. Since 1983, scientists have been able to change plants more quickly by changing their genetic(遗传的) material. Foods from plants grown in this way are called genetically modified(改变的) foods, or GM foods.
By changing the genetic material of a plant, it is possible to make new plants. They make plants which are strong against plant diseases. They can also help in our diseases; a kind of rice is being prepared , for example , which stops people becoming blind.
Rich countries produce GM foods because they are easy to grow and bring in more money. Poor countries are interested in them because they help produce more food.
GM plants are not natural. No one knows how good or bad they are,. Making GM foods is only one way of feeding people in 2050. There are strong feelings against them, because they are unnatural. They may feed people , then hurt them or their children later. But both rich and poor countries are interested in their use, and they are not going to go away. In 2050, we may think differently about them.

(1)、GM foods are made by                

A、farmers            B、workers C、scientists D、plants
(2)、What are the good things about GM foods  ?

A、They make plants strong against diseases.  B、They are unnatural. C、They can help in human diseases.   D、Both A and  C.
(3)、GM foods        .

A、are a quick way to produce food  B、grow in the wild C、are safe   D、are grown only in rich countries
(4)、Why do some people not like GM foods?

A、They are not useful.      B、They are not helpful. C、They are not natural.    D、They are not cheap.
(5)、From the passage we know that      .

A、GM foods will disappear one day in the future B、GM foods will not disappear in the future C、People will not be interested in GM foods. D、People will have to stop using GM foods
举一反三
 阅读下列短文,从每题所给的A、B、C和D四个选项中选出最佳选项。

If you've ever seen elephant seals(象海豹) lying on a beach, you might think all they do is sleep. But now scientists have discovered that when elephant seals are in the ocean, they hardly sleep at all. They just sleep for about two hours a day. 

Even though elephant seals are large animals, they have to be careful in the ocean. Near the surface(水面), predators like sharks and orca s are a danger. So elephant seals spend most of their time diving(潜水) deep underwater, looking for food. Usually, they will dive for about 30 minutes, then come up for air for just a couple of minutes before diving again. 

Scientists have wondered how elephant seals can sleep while they're at sea, since they are almost diving all the time. Animals like dolphins and sea lions have a special way. One half of their brain can sleep, while the other stays awake. But elephant seals are like humans- both halves of the brain need to go to sleep at the same time. So how do they sleep? 

To find out, a scientist named Jessica Kendall- Bar did a research. She created a special cap that could record the elephant seals' brain activity. The cap also collected information on the elephant seals' heart rates, how their bodies were moving, and how deep they were. Dr. Kendall- 

Bar and her team put the caps on thirteen young female elephant seals. 

The scientists learned that elephant seals steep in short times while they are diving. They only sleep for about 10 minutes at a time. They wake up in time to go up for more air. The scientists found that elephant seals only sleep for about two hours a day when they're in the ocean. That means that the rest they get once they return to land is very important, which helps them have energy again. Back on land they sleep for about 10.8 hours a day 

The researchers hope that their work will help to protect the places where elephant seals sleep when they're on land. 

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