5. 选C。读完全文我们知道地球上的水资源有限，所以大家都要节约用水。故选C。

4. 选A。A选项与C选项相互矛盾，则必有一个为正确选项。而从第3点建议(advice)可知，你可以沐浴只须五分钟来节约用水，若用10分钟则是浪费水。故选A。

3. 选D。由第5段中的句子Dirty rain, called acid rain, is also bad for plants animals and buildings.可知，acid rain(酸雨)的危害很大。 故答案选D。

2. 选B。短文第3段中介绍了全球70%被水覆盖，但只有1%才是饮用淡水。而世界上的很多国家和地区都缺水。所以选B项，即我们的生活用水很少。

1. 选C。从第1段中的句子She has no time to go to school可知，她根本没有去上学。故选C。

5. What’s the main idea of the passage?

A. Something must be done to prevent water form be­ing polluted.

B. Clean water means much to human beings and living things around us.

C. It’s time to take care of the water we use.

D. Water is the most important natural resource on the earth.

[答案及解析]

4. Which of the following wastes water?

A. We need ten minutes if we want a clean shower.

B. We should put in enough clothes when we wash them in washing machines.

C. You can keep yourself clean by having a shower for five minutes.

D. Don’t let the water run when we brush our teeth and wash dishes.

3. Acid rain _______.

A. is only bad for living things

B. can be produced in factories

C. doesn’t do harm to people, but it’s bad for plants, animals and buildings

D. doesn’t just do harm to human beings but to ani­mals, plants and buildings