1.  In some big cities, the people are especially short of clean water.

2.  Then we expect that we have plenty of clean water in the future.

3.  Clean water becomes less and less.

4.  Secondly, change the pollutted water into clean water.

5.  More and more people can drink clean water and live in tidy rooms.

6.  we should realize the gravity and come up with some effective strageries to that problem, reinforce the protection of our fresh water, clean polluted water .

7.  On that day, youth and children handing small bowls full of clean water sweep it to others.

8.  The clean water is used to vanish the evil.

9.  Among other things, we find it hard to get any more clean water.

10.  (t13-3)