If we usually forget to bring our card, we will be asked to recite our student number and tell us which college we are from. We have a good attitude, so that you can do it if you want to enter, and you can probably speak almost the same. Our school sells a kind of card called ordinary card, which looks very similar to the campus card, except that there is no photo and it is anonymous. It can be used to charge money for consumption in canteens and supermarkets. You can get one if you want, and the cost is about twenty or thirty. When you enter the library, it should be no problem to point the reverse side of the card at the security guard.