1、We have only one earth.But now,the environment becomes worse and worse.As you know,there's no enough clean water for people.So many of them lose their lives because of water.In a lot of countries,people have to cut trees for living.So there's nothing to keep water from running away.Also we have polluted the land,the river and the air.Some people may say:we are the masters of nature.Now the master seems to be confronted with problems that are far beyond his control.

2、the holes of the ozone layer make the earth less suitable to live for some creatures including human beings.Facing all the disasters made by ourselves,we have the responsibility to deal with the problem.

3、we must do something useful to protect our environment.We can plant trees and take good care of them.We can save the water and ask our parents to do so.We can't throw any litter onto the ground and we should collect them for recycling.If we take good care of our earth today,it will be more beautiful tomorrow.