What books should be selected for modern library collection?

What about my library? I prefer textbooks, which are introductory textbooks for a certain subject. First, if you want to delve into a subject, you must have time, energy and place to use it. Second, to graduate from a second-rate or third-rate university, you only need to read books that you can understand. As for classical Chinese and books with long titles, you don't need to spend more money. After reading it, don't show off in an ostentatious manner that you are professional, but at most say that you are getting started. We should know that the professional level of books published in the market has lagged behind the research institute for many years, and it is far from academic journals. Therefore, we should read with an open mind. Any discipline does not represent the whole truth, but only looks at the problem from one angle, which only brings us closer to the truth.