4. What kinds of human activities can cause damage to the earth? How can we reduce the damage caused to the earth?

人类破坏环境的行为可谓五花八门，乱砍滥伐、涸泽而渔等等，现代社会又发展到隐形阶段，譬如臭氧层正在遭受的无形破坏。如何减少这些人为因素对自然界的影响甚至是危害，是目前全人类共同的话题。希望考生能够通过解答这些问题提出一些可行的建议。

Candidate 1: In my opinion, greed is the root of all evil. People with greedy desire, in order to make more profits, endlessly exploit resources. They are shortsighted and eager for instant benefit. Some merchants cut trees to acquire wood, pour waste water into river, and catch animals for their fur to make money without realizing that the limited natural resources could be used up someday if they don't recycle. Then, there would be no more forests, clear water or air and living organisms. Therefore, form now on, we must adopt the strategy of sustainable development and learn to live in harmony with nature.

Candidate 2: Many human activities have caused damage to the earth, such as cutting down great numbers of trees, pouring waste water into rivers, dumping rubbish in the sea. There are simply so many actions that I can't enumerate one by one. In order to reduce the damage to the earth, we should do something in a peachful way. For example, we can still cut down trees, but every time when we cut down one, we should promise to plant two. Waste water must be treated by special processes before it is poured into the river. When it comes to the rubbish, we will think about recycling, which has been discoursed on for nearly ten years. It can protect environment, save power for us, and what's more, it can make the rubbish become useful!

Candidate 3: We live on the earth, and we are children of our Mother Nature. Our Mother selflessly offers so many things to us to live a better life. But we just want more and more from her, sometimes we even adopt extreme methods to harm our Mother. For instance, we cut down trees and exploit resources time and time again without recycling. At the same time, we leave useless things to the earth, which usually will pollute the environment severely. We are those selfish ones and think little of our Mother.

But when our Mother falls ill, can we live a good life? The answer is obvious—No! So, don't just sit back and leave the problems to the experts or the governments any more. As citizens of the Earth, we all have the responsibility and ability to preserve and sustain the environment we have. Only when we realize the importance of protecting our Earth, will the problems be solved in a more sensible manner.

三个答案的组织简洁有力，语言流畅。Candidate 1回答剖析了贪婪是一切罪恶的根源，同时升华到可持续发展战略的重要意义；Candidate 2提出了我们应采取的相应措施；Candidate 3则从感情入手，论证了人类和地球母亲的关系，以情育人，极易获得考官的认同。

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