To open a book, we must first look at the table of contents and chapter titles, and establish an overall framework for the book, especially the logical relationship and theme spirit, which can basically be reflected in the table of contents. When reading the main content, please make any marks and labels you want in the book, as long as you can understand them yourself. Don't be sad. Books are for you to learn knowledge, not for you to look good. Some people cherish books very much and are reluctant to draw or write. Finally, when they finished reading it, the book was cleaner than the face, and then they didn't know. This kind of love is not love, but a waste of time. After reading a book, you can't just read it, you have to have an output. You have to tell what one or two books are about, not only to know, but also to fall on the paper and on the keyboard. As the saying goes, a good memory is not as good as bad writing. Writing this time is equivalent to reviewing the book again. Even if this knowledge falls into our minds, it is our own.