It should be because of the differences in different textbooks: ① Version A and Version B are different in the knowledge content of the same module. For example, the classification of four prisms and the concepts of regular prism and regular prism in the first chapter of compulsory 2 space geometry are not only given in version B, but also used in exams. Version A is not given. This chapter also has the concepts of spherical distance and convex polyhedron given in version B. As the same knowledge point, ② has different positions in the textbook. For example, the principle of ancestral source is mainly studied and explained in the B version of the course. Version A is given in Exploration and Discovery. There is also the third chapter intercept equation, in which version A is given in the example and version B is given in the exercise. There is also the distance between two parallel lines. Version A is given in the exercise and version B appears in the example. ③ The emphasis of training in the same chapter is different. The A version of Geometry of Space pays attention to the examination of spatial imaginative thinking, and more is to combine practical problems. Version B pays attention to the extension of concepts and cultivates students' ability to analyze problems and think logically.