1. This book has been reserved or borrowed by other readers and cannot be borrowed again.

The number of books borrowed by readers has reached the upper limit, and some books need to be returned before they can be borrowed again.

3. The reader's library card has expired or is in a frozen state, and you need to deal with related issues before you can borrow it again.

4. The reader fails to pay the arrears or compensate for the losses according to the regulations, and it is necessary to solve these problems before borrowing again.

5, library system failure or maintenance, temporarily unable to borrow books.