C416

The first floor was a very big hall, with all kinds of books divided into different categories. After Pei Yin and Pei Kun entered the room, they directly went over to the teaching area and found a few books on teaching physics and physics, plus a few problems books. Pei Kun looked at the thick stack of books with difficulty, and said to Pei Yin: "Second Sister, there are a lot of books here