Don't think that the topic will be complicated (except in special circumstances, for example, you know that a topic is difficult), and don't think that it will take 10% to 18% to solve the topic. This is not only because we need psychological hints to encourage ourselves, but also because math problems can be endless, but if no one can do them, they should not appear here (exercises and exams). Explain that you can do it within your power. I coached a junior high school student in plane geometry in high school. I found that he often tried an idea. He had drawn seven or eight auxiliary lines, but he didn't give up. I told him that it was time to think about whether it was wrong from the beginning. He always said to me, "What if? What if? " I think we should consider 9999/ 10000 first, and then consider 1000.