题目内容
阅读短文，掌握其大意，然后用方框内所给的词 的适当形式填空，每个词限用一次。
reuse | how | once | make | cover |
stop | face | pollute | clean | drink |
The world is not only hungry but also thirsty for water. This may seem strange to you, since nearly 70% of the earth’s surface is 1 . with water. But about 97% of that is sea water, or salt water.
Earth Day is on April 22. But on all other days, we must also remember 2. important water is. The water that we use is the most important national resource on the earth. Today we 3. serious water problems. One of them is water pollution. Polluted water is very bad for people to 4. . And dirty water is bad for fish, too.
How do cars and factories make our water dirty? First they 5. the air. Then when it rains, the rain water 6. our drinking water dirty. Dirty rain is also harmful to plants, animals and buildings. Scientists say that in 30 years, more than half of the people in the world won ’ t have enough 7. water. We all have to learn how to 8. wasting water. One of the first steps is to develop ways of 9. it. Today in most large cities, water is used only 10. and then sent out into a sewer system (下水道).From there it returns to sea or goes underground places.
1. covered 2. how 3. face 4. drink 5. pollute
6. makes 7. clean 8. stop 9. reusing 10. once
