The second volume of the ninth grade, Henan mathematics buys a famous school classroom, Henan special edition mathematics, the second volume of the ninth grade, Beijing Normal University BS synchronous practice middle school teaching assistant is good. Classrooms in prestigious schools are all comprehensive papers, with basic questions, intermediate questions and difficult questions, which are suitable for students who want to consolidate their foundation and improve their grades at the same time. At the same time, because it is divided into local special editions, the topic selection will be more biased towards local test sites, and the practice efficiency will be higher.