I wonder if you are a student in Tsinghua. But you can sit on any table in the library, as long as you can occupy it, it is generally not difficult to occupy it. Nobody will care about you. You can also enter the library at will and read the books in it at will, but if you are not a student or teacher in our school, that is to say, you can't lend it out without a library card. This is the largest reading room in 234. Here's the situation. There is a magazine room on the fourth floor. You can only go in with a permit, but you can't lend it out with a permit.