81.  We must take steps to protect our fresh water.

82.  The government must make laws to protect the resource of fresh water.

83.  For example, we can plant the trees to protect the source of water.

84.  Second is to protect the resource of fresh water by planting trees.

85.  Second, we must protect our surroundings and prevent fresh water from pollution.

86.  In order to protect our Earth, we must prevent pollution.

87.  If all the people in the world come to protect our Earth, it will get more and more beautiful.

88.  City should take effective measure to protect our land.

89.  What I am studying is to protect environment.

90.  So we have to protect environment.