Useful. Because textbooks are basic knowledge, we should review the basic knowledge before delving into difficult topics in senior three. Textbooks are undoubtedly good things to review the basics, and they are original. And most of the exams are basic questions. Even the mathematics of the 2022 college entrance examination is inseparable from the basic questions. As the saying goes, it is easy to sharpen your knife and cut wood. After reading the textbook, it is easy to do the problem. Believe in yourself, come on!