When I was in high school, there was a book called "handbook of important and difficult points" in three subjects of mathematics, physical chemistry in high school, which was quite classic. . . In particular, Chemistry, edited by Wang Houxiong, is a classic among the classics. . .

Almost ten years ago. I don't know if there are any more. . . Go to Dangdang to search. If it still exists, start decisively and ensure your satisfaction. . .

If you want to go further and engage in mathematical olympiad, then you only need to search Dangdang for all kinds of books written by Mr. Denton, buy them and chew them slowly. . . The positioning of this series is at least the provincial first prize and even the national first prize. . . Please think twice before you act, or you will be vulnerable. . .