Wan Wei is very difficult. The required questions contain a large number of exercises with a wide range of difficulties, ranging from basic questions to difficult questions, aiming at comprehensively improving students' problem-solving ability and test-taking skills. The difficulty can be selected according to the actual situation of students, which is suitable for students at all levels to carry out targeted exercises. Wan Wei pays more attention to depth and breadth in topic design and topic selection, covering more advanced knowledge points and complex problems, aiming at challenging students' thinking ability and problem-solving skills. This design makes Wan Wei's questions more challenging than the required ones, so the difficulty will increase accordingly. Wan Wei pays more attention to simulating the real test environment and test style, and can simulate the test types and difficulty distribution of various tests to help students better adapt to the requirements of real tests.