A essay need be polished~?

[Prof]

Donald removed from your essay some common grammatical, spelling, and usage errors but essentially left it as you wrote it, in imperfect English that is common to oriental non-native speakers and writers. It is difficult for non-native speakers to understand the nuances of the use of articles (a, an, the) in the language. This may be a valid strategy because schools will recognize that you wrote the essay rather than hiring someone to do it for you in perfect English form. In general your essay conveys good thinking on your part. It should work well.

My suggestion is to use Donald's version, but include your introductory paragraph, and change the very poor forms of Firstly, Secondly, and Thirdly to First, Second, and Third.

Here is my edited version of your introduction:

Tertiary education has long been a center of public attention. It has been argued that schools should advocate work preparation for graduates before they enter the society at large. From my perspective, I agree.

Students are already members of society, so your sentence lacks logic. But they are members of the student segment of society and they become members at large after they graduate. My version eliminates this logic error and uses articles correctly. Changing from singular to plural also improves the sentence. Appending this introduction to Donald's version of your essay makes your essay a winner. Best of luck.