1, because the librarian of Beijing Shang Library is generally responsible for borrowing books, so it won't be too tired, because the staff usually borrow books, and the flow of people is not big.

2. Relatively speaking, the health work of the library is the most important. After all, it is a place for scholarly reading. It's tedious to mop the floor and clean the bookshelf, but it's equivalent to exercising.

There is a time limit for the busyness of the library. Students are often in the climax of borrowing books after school, which makes them nervous. After that, they will restore calm.