Since I am studying science, the foundation should not be too bad. First of all, the knowledge in the book is the key. You must master the knowledge in the textbook. In the process of mastering knowledge, do the questions according to your own level, and constantly improve the difficulty of doing the questions according to your own level, so that you will gradually find that your knowledge will slowly return. . . I also study science. I think learning math is very important. If you master and understand the knowledge points, you can improve your math level. . .