1.  Preventing the water from being polluted, controlling the rise of popution and making most of the seas are also the ways in which we must do immediatly .

2.  First, we prevent water from being pollute,.

3.  Secondly, the measures must be taken to prevent fresh water from pulluting , and we must controll the population in the world.

4.  Facing with this problem, we should prevent fresh water from being pollutted , and use the fresh water efficiently.

5.  Then, we shall prevent fresh water from being polluted.

6.  We don't waste water, and we ought to prevent the water from polluting .

7.  We should take steps to prevent fresh water from being polluted.

8.  On the other hand, we must effectively prevent the water from being polluted and wasted.

9.  Then we should take steps to prevent fresh water from being polluted.

10.  Second, we ought to prevent fresh water from being polluted.