as we all know, the earth is a planet almost covered by water，and it is water made every thing on the earth lively.water is also one of the important part of our environment.though，is there really so much water for us to clean，to produce many things，to play with? how much water are there on the earth then?
most of the water is in the oceans or locked away as ice.the largest volumes of fresh water are stored underground as groundwater，imagine there is only one barrel of water in the world，then there is only a spoon of it on the land，and the water we can use is only a drop of it.now i have to remind all of you here that the single drop of water is never as clean as before，it has been polluted severely by our human beings.
there is a very beautiful river in paris.it is the seine，it runs across the city，people drink coffee, chat on the bank in the day，at night，they enjoy the beautiful scenery in the boat，songs from the river fly into the sky made the river more attractive, the seine is a famous symbol of france;on the west coast of pacific ocean there lies the modern city shanghai，another river which used to be a very important transportation route runs through the center of the city，people respected and regard it as"mother".it is the"suzhou river，but l believe that few of you would sit beside it，people will be scattered by the terrible smell of water when walk by.i have to say it is extremely dirty! and we all know that a lot of beautiful rivers in the world also are sharing the same fate with suzhou river. who is the devil? i can't help asking.
many human activities and their by-products have the potential to pollute water. please have a look along the banks of the river, large and small industrial enterprises discharge dirty water, tons of garbage were thrown into the river, the water contained so much that it can't clean itself. compared with the dramatic development in many sides of shanghai, the suzhou river has become a black point of the appearance of city.
fortunately, the government has control the situation now, we are happy to see some parts of the river has become clean again, and we even can find fish sometime.
the unique earth is the only planet full of lives, the water is just like the blood in the active body, protecting water is saving ourselves. not to waste a single drop of water, otherwise, the only drop of water we could keep in the future would be our tear!
my dear friends, mankind still faces a great difficulty in solving the problems of the environment and development, and there is a grand task to perform and along way to go. the middle school students in china will always cooperate with the young people of the world to protect the environment.