【题目】Do you know about DNA? Here is an introduction of it.

DNA is short for deoxyribonucleic acid. It contains genetic instructions. These instructions are used in the development and functioning of all known living organisms(有机体). That's to say that your DNA decides what you are like. Perhaps this is a little bit difficult for you to understand. Here is an example to explain it more clearly. Before you were born, your DNA had already decided you would have two hands and that each hand would have five fingers. Your_hands_would_help_you_hold_things_and_do_many_other_things.

However, DNA is more than that. We get our DNA from our father and mother. That is why we look like our parents and are not like others'. Also because of different DNA, Chinese people look different from Americans. Chinese people have black hair and eyes, but many Americans have blue eyes and blond hair. Though we have discussed many things about DNA here, there is still a lot more to know about it. If you would like to know more about DNA, you should go on the Internet. Perhaps the website will help you.

(1、2题完成句子;3题简略回答问题;4题写下全文的主题句;5题将文中画线句子译成汉语。)

1Americans look different from Chinese because ________________

2Your DNA decides ________________

3Whom do we get our DNA from?

________________________________________________________________________

4________________________________________________________________________

5________________________________________________________________________

【题目】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. But 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 prevent human 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. 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.

1GM foods are made by________.

A. farmers B. workers

C. scientists D. plants

2What are the good things about GM foods?

A. They make plants strong against diseases.

B. They are unnatural.

C. They can help prevent human diseases.

D. Both A and C.

3GM foods________.

A. are a quick way to produce food

B. are grown in the wild

C. .are safe

D. are grown only in rich countries

4Why 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.

5From 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

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