Xu Jingshu, from Class 1, Grade 2, doesn't say many sarcastic words. If she hadn't been taken out of every math class by the teacher and made to stand, she would have been a transparent person in the class. "Jingshu, were you made to stand by Wei again?" Lao Ma, the head teacher, said helplessly when he saw the familiar figure when he led the transfer student Chu Youning to the door of the class. "Yes." Xu Jingshu responded calmly, not feeling embarrassed because of the presence of outsiders. Later, during a monthly exam, Lao Wei looked at Xu Jingshu's perfect scores in other subjects and compared them with the nearly blank big questions in her math paper. The person concerned was still looking out the window in a daze, and shouted angrily: "Xu Jingshu, take the paper for me and go out to reflect! Come back to my class when you finish reflecting!" So, that afternoon, someone saw Chu Youning, the god of learning, teaching Xu Jingshu mathematics in the study room upstairs...