Textbook A and Textbook B are two different versions of mathematics textbooks. They are different in content arrangement, which may involve chapter order, arrangement of knowledge points, selection of examples and exercises, etc. In addition, the two versions of the textbook may be aimed at different groups of students, so the difficulty of the topic may be different. Version B may pay more attention to in-depth understanding and application, and the topic is relatively difficult, while version A may pay more attention to mastering basic knowledge and solving simple problems. This difference may affect students' learning progress and difficulty adaptability in the learning process.