1. This book focuses on the excavation of invisible knowledge in the textbook, the expansion of knowledge and methods, and the gradual explanation, so that students can learn through all necessary test sites inside and outside the textbook.

2. Emphasize multiple solutions to one question, practice more to one question, explore and summarize the laws and methods of solving problems, and directly hit the key and difficult points, so that students can easily break through the difficult and error-prone points.