11.  When it rains, we will have fresh water.

12.  And we have other water, such as river water.

13.  Then in order to avoied having no water to drink, what should we do?

14.  If everyone can do these, we will have enough water.

15.  In short, I believe that we have enough water in the future.

16.  Because they believe that when it rains, we have water, and we can get water from the river and the well .

17.  Now, there are also many people in the world who think that we have enough water on the earth.

18.  But it doesn't mean we have enough water to use every day.

19.  If these steps work, we would have enough water in future.

20.  Since man exists, the nature feeds us unremitting and asks no repay She provides forest to us, so we have wood to lit up and then have warth and light; she provides river and we have water to drink; she gives us animals and fruit to eat.