1, topic quality: Xueba black-and-white topic is written by experienced teachers or professional teams, and the topic quality is high. The topic covers all test sites and difficulty levels, which can help students fully understand and master knowledge points.

2, knowledge coverage: Xueba's black and white questions are more comprehensive, covering all the knowledge points of the exam. It is helpful for students to systematically review and consolidate their knowledge and improve their ability to take exams.