In fact, all levels are suitable, and the important thing in learning is not teaching AIDS, but seriousness. I used this teaching aid. Questions are simple and difficult, and they are all explained. Students with unsatisfactory grades can accumulate experience by doing problems slowly. Don't be impatient. If they can't, they can read the explanation or consult the teacher. Students with good grades can learn from the explanations in the book and improve their habit of doing problems, so that they can make achievements at a higher level. The key to study is seriousness and concentration.

Junior high school seems to be the middle point of the book, which feels good. I wonder how the book is now. Personally, I think this book is suitable for general review.