Baidu Cloud about the People's Education Press high school Chinese explanation video. Only compulsory course 1 is acceptable.

Kuaixue.com is fine. They have the High School Affiliated to Peking University, the High School Affiliated to Tsinghua University, Beijing No. 4 Middle School, famous teachers from the High School Affiliated to Renmin University, and teaching videos of nationally senior teachers, covering important knowledge points, synchronized pre-class previews, and in-class Simultaneous in-class lectures and after-class test practice; you can check the official website, many schools use it, and teachers also use it