注释：
1、提出论题
2、说明现状
3、理由一
4、理由二
5、理由三
6、理由三引起的后果
7、解决方法
相应作文：
Pollution of environment These days we often hear that (our living conditions are getting more and more serious because of the destruction of our environment ).It is common that (many trees and animals are near extinction, and the all-important food chain has been destroyed.). Why does such circumstance occur in spite of social protects? For one thing, (the population of the world is increasing so rapidly that the world has been so crowded. ).For another,(the overuse of natural resources has influenced the balance of natural ecology ). What is more, since (the industrial revolution ),it is natural that (a great number of factories have been springing up like mushrooms. The smoke and harmful chemicals released from factories also pollute the environment). To solve the problem is not easy at all, but is worthing. We should do something such as (planting more trees, equipping cars with pollution-control devices and learning to recycling natural resources )to improve the present situation, and I do believe everything will be better in the future.