阅读理解。 You know you have to read 'between the lines' to get the most out of anything. I want to tell you something important during your reading. You shouldn't mark a book which isn't yours. 1_____ If you think it useful to mark books, you will have to buy them. There are two ways in which one can own a book. The first is to get the right by paying for it, just as you pay for clothes and furniture. But full ownership comes only when you have made it a part of yourself. 2_____ There are three kinds of book owners. The first has all the best sellers -- unread and untouched. The second has a great many books. 3_____ The third has a few dog-eared (翻折的) books, which are marked from front to back. Why is marking a book necessary? First, it keeps you awake. In the second place, reading is thinking. 4_____ The marked book is usually the thought-through book. Finally, writing helps you remember the thoughts you had, or the thoughts the writer expressed. If reading is to learn anything more than passing time, it must be active. The book you read for pleasure can be read in a state of relaxation, and nothing is lost. But for a great book, rich in ideas, reading must be active. 5_____ You should come up with an understanding of what you have read. A. You can't let your eyes move across the lines. B. But most of them are as clean as the day they were bought. C. And thinking can express itself in words, spoken or written. D. People who lend you books expect you to keep them clean. E. The best way to make yourself a part of it is by writing in it. 1.______2.______3.______4.______5.______