The teacher in the library wants to recommend a good book to his classmates. He can first concentrate the students' attention, that is, he can play an audio or video in the library to attract everyone's attention, then explain that he is a teacher, and then he wants to recommend a good book to everyone present.

Or go indoors and explain your identity directly to everyone. Then I can simply recommend the good book in my hand to you, and then recommend you to read this book or buy it.

It also shows that I am not selling like a salesman, but I just want to let everyone have more contact with this book, because the quality of this book is really beyond the level of other books. This is the saying that the teacher of the book club wants to recommend good books to his classmates.