I think it's quite reliable. I didn't do well in the middle school entrance examination, so my mother bought me a complete interpretation of the bear textbook for me to make up. Personally, I feel that this book is characterized by a comprehensive and detailed explanation of knowledge points and test sites, and it also teaches you the methods of doing exams, and the unit summary is also done well. Now I'm in the top five in my class, and I feel very helpful.