101.  With the population increasment , more and more people need fresh water.

102.  When industry develops at high speed, fresh water are used at the same speed .

103.  Worst of all is the pollution that makes fresh water can't be used.

104.  First, we mustn't waste fresh water.

105.  We hope that we can truely make fresh water unlimitted .

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

107.  In fact, fresh water is not so sufficient as we think.

108.  It is well known that fresh water is the origin of life, so it is the most precious treasure to our human beings.

109.  And on the other hand, scientists are trying to search for better source of fresh water.

110.  Many people think that fresh water in our world is abundent and it can not be used up.