71.  We can develop new ways of using water, and improve the circle of water.

72.  First, I think we should reduce the quality of using water.

73.  But as we know, only fresh water can be used to wash, cook and so on.

74.  On the other hand, we shall try to use sea water instead of fresh water or get fresh water from sea.

75.  But many people think that the fresh water can be used for good, which is out of the fact .

76.  We shall use water properly, and can not waste it.

77.  Even From seas, according to this opinion, human can use water freely.

78.  Then, we must save up the quantity of using fresh water.

79.  Secondly we should use fresh water effectively.

80.  Less and less water can be used.