Of course, it is more difficult to improve the experimental class. There are many expanded topics, which are designed for some students with learning ability and are not suitable for middle school students. After all, after you have done it several times, you may be as tired as Olympiad. Because it has many classes and many topics, it can do what it can. It won't help if you can't finish it or can't do it after you buy it home. Generally, I want to do well in the exam, focusing on training myself to master knowledge points on basic questions. These extended questions are to activate my thinking. To put it bluntly, they are doing the basic questions better for you. They are a form to help you learn math. After all, most Olympic math problems are of little practical value to your later life.