How did the teacher find out when he checked the students' endorsements and the peers silently mentioned the books?

It is because this endorsed male classmate saw his companion holding a book behind his back and smiled silently, and then the teacher found a classmate holding a book under the table, so this scene attracted the attention of netizens and made me feel quite funny. Some people also commented under the video that one secretly helped and the other openly betrayed. I think this comment really summarizes the video characters on the screen. I believe that everyone should have done such a thing in our student days! I silently reminded my companion when he needed help. I remember when I was in the fifth grade of primary school, when math was not very good. One day, when I was drawn by the teacher to do the problem, I was actually very upset. I am a very timid person. When I stepped onto the platform, I was shaking all over. I started to do the problem, and looked at my partner behind me after I finished. When I was doing it above, he was doing it below, and then he gave me a firm answer, that is, nodding. When I saw him nod, my heart was at ease. In high school, the history teacher was a person who liked to ask questions. He will ask the rest of the last lesson and let us recite it to him, or tell him directly. At that time, the teacher was on the blackboard, and we whispered below, afraid that he was wrong, afraid that the teacher would get angry at a word, or afraid that he didn't recite. Whenever I think about it, I think it is a memory of my school days. Moreover, it is precisely because of these funny memories that my school life has become more and more colorful. Although it's a little wrong, I think it's a manifestation of students' helping each other when we were students, and I think it's also a great memory.