1.  And pullotion of the water have reduced the water available greatly.

2.  People often take it for granted that fresh water are available to meet our use without limitation.

3.  We need more fresh water while less fresh water is available, so the shortage of fresh water is necessarily the case .

4.  Many people take it for granted that fresh water is available for ever.

5.  The most important factor must be that we have polluted the water resource so seriously that there is less fresh water available today.

6.  On the one hand, with the increasement of porpulation and the advancement of modern industry, more and more fresh water is needed, on the other hand, the water pollution is so serious that the available fresh water is Decreasing, which results in the shortage of fresh water.

7.  Most of the people think that our fresh water can be available for ever and fresh water from rain fall , rivers or wells is easy for us to use whenever we want.

8.  On one hand, there isn't so much fresh water available on the Earth , as people had thought about .

9.  Meanwhile, the water pollution makes the water available less.

10.  First, an increase in population makes the shortage of fresh water available.