51.  the worth fresh water is limit and the use of it increase , so the fresh water is short.

52.  Since there is plentys of fresh water in rivers or from raining or under the ground, people take for granted that it is no use worrying about the shortage of fresh water.

53.  Thirdly, we hope scientists can find efficient ways to recycle water or make use of new water resource such as the ice in Atlantic.

54.  So people think fresh water is enough to use.

55.  Certainly, we should save fresh water and do our bit to reduce the use of water in industry.

56.  Fresh water use in industry is increasing.

57.  They think that water is enough to use.

58.  On the other hand, we should try our best to improve the method of converting sea water into fresh water, so that the sea water can be made good use of.

59.  It May lie in serval factors: the increase of popullation , the increase use of industries and pollution.

60.  With those factors, the use of fresh water is increase .