Are undergraduate grades important? Everyone knows that high marks earned at different schools or under different instructors can indicate very different levels of achievement. One professor may be a hard grader, while another is very generous. Some schools have high standards, whereas others don’t. And at all universities there is a constant tendency (倾向) towards grade inflation (giving ever more high marks). Although this tendency is fought fiercely at some universities, it is allowed to go unchecked for long periods at others.Another point raised against grades is that they hardly predict how much graduates will be earning 15 or 20 years after getting their degrees. As many studies have shown, there is only very weak link between undergraduate’s grades and future wealth. People who get good marks tend to go into profession, not all of which are highly paid. The link between undergraduate grades and success in business, the most common road to wealth, is in fact zero. Many ordinary students become successful businessmen, while some brilliant and capable graduates (creative youngster, not students with special skills in passing exams) take up relatively low paying but interesting or satisfying careers. The general population sees one thing very clearly that good grades don’t translate in any direct way into big money, and for better or for worse, the standard of “success” for countless Americans is the possession of wealth.The result is certain modesty about good grades in America among those who get them. A student’s parents may be proud of his marks, but seldom will the student himself risk being called a “grade-grubber” by paying too much attention to his academic success. High marks are not something to be advertised to the world except on resumes (个人简历), and anybody who is crazy about them is likely to be viewed with contempt (鄙视).What is the main purpose of the passage?