You know you have to read "between the lines" to get the most out of anything. I want to persuade you to do something equally important in the course of your reading. You have to "mark between the lines". By marking you can make the most efficient kind of reading. There are two ways in which one can own a book. The first is the property   right you have by paying for it, just as you pay for clothes and furniture. While full ownership comes only when you have made it a part of yourself and the best way to make yourself a part of it is by writing marks on it. Why is marking up a book _ to reading? First, it keeps you awake. Second, active reading is thinking, and thinking tends to express itself in words. Finally, marking helps you remember the thoughts you had, or the thoughts the author expressed. Reading a book should be like making a conversation, a conversation between you and the author. Although he knows more about the subject than you do, don't let anybody tell you that a reader is only on the receiving end. Understanding is a two-way operation. Reading doesn't mean being a passive empty receiver, the reader has to question himself and question the author. And marking a book can show his own judgment on author's opinion: agreement or difference. The author thinks "marking between the lines" is   _  .
the most important of all more important than "reading between the lines" as important as "reading between the lines" not so important as "reading between the lines"