Off campus, right? Hehe, you can enter at will. There are many tables on the fifth floor without certificates, but it is difficult to find seats, either for postgraduate study or for some cattle people to study by themselves all the year round. You can also go to the lecture hall to teach yourself. As long as there is no class, just find a seat to study. The unattended library seems to be open from 8: 00 a.m. to 1 1: 50 p.m. and from 2: 00 to 5: 50 p.m., and the fifth floor opens earlier.