11.  In order to not waste fresh water, we should manage to make full use of it.

12.  First, we must make full use of fresh water.

13.  In short, we must make full use of our fresh water in our global .

14.  I think, firstly, we should make full use of fresh water and don't waste a drop of water; Second, we should not make water poluted again, we should do our best to make it useful .

15.  We should make full use of fresh water.

16.  Thirdly, we must make full use of our fresh water sources.

17.  On one hand in our lives, we should make full use of the fresh water and not waste a little water.

18.  We must make full use of water.

19.  First, I think, we should make full use of every drop of water.

20.  Second, we should make full use of it, not waste it.