注意：1.信的开头与结尾已经给出，不计算在总词数内。

　　2. 字数要求: 120左右。

　　人口膨胀population expansion;过度开发overdevelopment。

　　Dear editor,

　　Environmental problems are becoming more and more serious all over the world.

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　　Yours truly

　　Li Hua

　　One possible version

　　Dear editor,

　　Environmental problems are becoming more and more serious all over the world.

　　With the development of industry and agriculture, cars make great noises and give off poisonous gas. Because of population expansion and overdevelopment, resources has become less and less. Trees on the hills have been cut down, and waste water is being poured continuously into rivers. The whole ecological balance of the earth is changing. Massive destruction of environment has brought about negative effects and even poses a great threat to man’s existence.

　　We must face the situation that exists and take actions to solve our environmental problems. We hope that all these measures will be effective and bring back a healthful environment.

　　Yours truly

　　Li Hua