Study hard and don't expect to do the problem when you see the answer. It won't do you any good! During the final exam, you always feel that the topic seems to have been done, but not knowing how to do it will interfere with your thinking. Therefore, high school students, especially in mathematics and physics, must not have the habit of reading the answers and doing problems, because you always feel that you will, will make you take it for granted, and will make you self-righteous! !