Cai Dejin and Li Shangze are both teachers. Cai Dejin is a top math teacher in high school. Graduated from Sun Yat-sen University, he won the second prize of Guangdong High School Mathematics Competition and the first prize of National High School Mathematics Competition. Li Shangze, Master of Communication and Information System, University of Electronic Science and Technology of China, is a first-line teacher in Chengdu, Sichuan Province, with three or seven years' teaching experience.