题目列表(包括答案和解析)

 0  239073  239081  239087  239091  239097  239099  239103  239109  239111  239117  239123  239127  239129  239133  239139  239141  239147  239151  239153  239157  239159  239163  239165  239167  239168  239169  239171  239172  239173  239175  239177  239181  239183  239187  239189  239193  239199  239201  239207  239211  239213  239217  239223  239229  239231  239237  239241  239243  239249  239253  239259  239267  447348 

12.(   ) 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.

试题详情

11.(   ) GM foods are made by ________.

A. farmers   B. workers  C. scientists   D. plants

试题详情

10.(    ) Which of the following is true?

    A. Hunger is the only problem in our world.

    B. Water shortage is the only problem in our world.

   C. Scientists don’t want to spend money solving the water problem.

   D. Scientists have been working hard and have made much progress in solving water problem.

(C)

   Today there are 6 billion people on the earth. By the year 2050 there may be 12.5 billion. This is a lot of people to feed. We need more food.

   One way to produce more food is by 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 material (遗传物质). Foods from plants grown in this way are called genetically modified foods (转基因食品), 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 (准备), for example, which stops people from 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 very interested in their use, and they are not going to go away. In 2050 we may think differently about them.

试题详情

9. What is the writer mainly talking about in this passage?

     A. The ways of getting fresh water.

    B. How to use fresh water in our daily life.

    C. All people in the world should save water.

D. Different ways of making water in different places.

试题详情

7.(   ) From this passage we know fresh water ________.

    A. only comes from the rain    B. can be used in many ways

    C. can be found in many factories  D. is needed by more and more people

(   )8 The word shortage in this passage means ________.

    A. being enough  B. being short of  C. being short for   D. being less

试题详情

6.(   ) Where does the fresh water people need come from?

    A. Sea water.  B. Rivers and lakes.  C. Underground.  D. Both B and C.

试题详情

5.(   ) Memory is ________ that we keep in our mind and carry about.

     A. the best diary       B. the best camera

     C. a great help           D. a beautiful picture

(B)

   The world is not only hungry, it will also be thirsty for water. About 97% of water on the earth is sea water, or salt water. Man can only drink or use the other 3%of the fresh water (淡水)which comes from rivers, lakes and underground. On the other hand, because the number of people in the world is becoming larger and larger, more and more fresh water is needed. So water shortage becomes a big problem.

   How can we work out this problem? Scientists have found some ways to turn salt water into fresh water. One important way is to boil (使达到沸点)sea water with high heat until vapor (蒸汽)rises, leaving the salt. In this way, a lot of fresh water can be made quickly.

   But heating is not the only way to get fresh water. Other ways are tried, for example, digging deep wells, keeping rain water and preventing rivers from being polluted.

   Which way is the best? To get the most fresh water for the least money is the best.

试题详情

4.(   ) _______ can take photos of what can be seen, felt, heard, smelt and tasted.

     A. A camera      B. Memory  C. A diary       D. A man’s mind

试题详情

3.(   ) The children who live abroad with their parents can learn two languages more easily because _________.

    A. they are very clever  B. they have good teachers

    C. they have more chances to use these languages  D. they have a better life

试题详情

2.(   ) If you have a good ________, you’ll have less difficulty in learning something.

     A. teacher        B. camera        C. memory       D. family

试题详情


同步练习册答案