41.  The population is increased and every one of us need fresh water.

42.  First, now population increases very quickly and more people need more water.

43.  Second, with the development of industry, more water must be needed.

44.  Second, with the development of the industry, more and more factor need fresh water.

45.  We need fresh water, such as rain water, river water, and so on, but it is limited.

46.  In city the more factories were founded and also need more water .

47.  So more water is needed.

48.  Water is also needed in industry.

49.  Today, fresh water is needed in many places.