First, it is relatively cheap to buy second-hand books. Second, former classmates will inevitably take notes, which is more conducive to their own study. Second-hand books can generally be bought in Taobao, Pinduoduo and the school's leisure groups.

When I was a freshman, everyone would buy textbooks honestly. Later, on the road, I saw many seniors holding photocopied textbooks, which were copied by the school copy shop. It costs a few cents to print a page, and it costs about ten dollars to print a page.

Then I realized that I didn't have to buy textbooks at school. I think copying textbooks may infringe copyright, and the copied version is only in black and white, which looks ugly. So I prefer second-hand books to photocopied books.

Using second-hand books can save resources and protect the environment to some extent. I don't know where I saw some foreign textbooks for primary and middle school students before. The main reason abroad is that teaching materials are particularly expensive.