李贺七岁作诗:英语的一篇文章,求大家修改...

People's ideas of beauty are changing all the time.For one thing, the Chinese thought the fatness of a woman was beautiful long time ago. What is "beauty"? One idealist of two major schools of philosophy thinks that"beauty" is the sympathy of its own definition of beauty. , A materialist from annother school thinks it is a reflection of object's existance. At all events a "perfection of beauty" exists among the people. Innumerable people desire this "perfection". They use the science and technology nowaday to "enhance" themselves. But lamentably the technology is only simple operation which changes their appearance. It is dangerous during the operation and after it.For example infection, inflammation will harm their health. The operations are not so precise like the cell division which is controlled by the DNA.

Like materialists I think beauty is only a refection of existance. "beauty" is only created by the most people. Only wisdom is eternal for me. So I'll be against a plastic surgery, unless it is very necessary.
整体思路不错,只是语言欠精练,改过后应该可以用了.

The beauty-ideal (什么叫beauty-ideal? doesn't make sense) of people changes all the time, e.g. (正规writing不要用"e.g.") the chinese thought the fat women were beautiful for some hundred years ago (for some hundred years ago??).
可改为：To people, the term "ideal beauty" changes all the time, for example, the Chinese thought that fat women were beautiful for hundreds of years.

What is "beautiful"? The idealism, one of the two major schools of philosophy, believes "beautiful" is the sympathy of the own definition of beauty and the object (sympathy of the own definition of beauty and the object??? 你想说什么 最好用中文打出来).
可改为：What is "What is "beautiful"? Idealism, one of the two major schools of philosophy believes that "beautiful" is a desbription used to show sympathy towards the object.

The other school, the materialism, believes it is a reflection of object's existance. At all events a "perfection of beauty" exists among the people. Innumerable people desire this "perfection". They use the science and technology nowdays to "enhance" themselves. But lamentably the technology is only simple operation which changes the appearance. Risks existent during the operation and after it(for example infection, inflammation etc.). The operations doesn't so precise like the cell division which is controlled by the DNA.
可改为：The other school, materialism, believes that "beautiful" is a reflection of the object's existance. At all events, a "perfection of beauty" exists among people. Innumerable people desire this "perfection". They use science and technology nowadays to "enhance" themselves. But lamentably, technology is a simple operation which only changes the appearance. Risks exist during and after the operation (such as infection, inflammation etc.) The performance of the operations are not guaranteed to be precise and secure, like the cell division controlled by the DNA.

Like the materialists I think the beauty is only a refection of object's existance. "The beauty" is only created by the most people. Only the wisdom is eternal for me. So I'll be against a plastic surgery, if it isn't necessary. (okay,既然你的文章的main idea is to convince people that plastic surgeries are not good, then you should mention it in your first paragraph as your topic sentence. 第二 你没必要说"if it isn't necessary" because 换言之you're saying 如果necessary的话，你会support plastic surgery 但是在文章里 你并没有offer explanations for this fact - 也就是如果plastic surgery is necessary, you're going to support it.)
可改为：In conclusion, like the materialists，I think beauty is only a reflection of an object's existence. The term "beauty" is created by people. In my opinion, only wisdom is the only eternal thing. Therefore I am against plastic surgery.

在你的第一个paragraph里 You should include topic sentences and thesis statement 来告诉readers你这篇文章要讲什么，like:
To people, the term "ideal beauty" changes all the time, for example, the Chinese thought that fat women were beautiful for hundreds of years.（到这儿你写得很好 后面可以加）Today in our society, people often look for ways to shape their beauty. Scientifically, we're introduced to a new method of "beautification": plastic surgery.（这样在下面的文章里面 readers 就会知道what are you going to talk about）