To answer you again, it's really not suitable. Don't trust the propaganda of the merchants. It can be said that most of the competition counseling books published by Zhejiang University Press have a chaotic system, complicated methods and unclear essence. Mathematics is suitable for East China Normal University Press or Hunan Normal University Press. You have mastered the classic competition questions, and it is basically no problem to recruit yourself. For example, Tsinghua copied the original IMO questions in 2008, many of which are old questions used in competitions.