Forget about keeping your book clean and neat. Use your margins to write questions and answers to the questions. Try summarizing key points in your own words. The process of writing down information or ideas will help you retain the information and your notes will work as a study guide when you are reviewing for an exam. Use your margin notes and the illustration to ask yourself questions.
Some students find that reciting the answer aloud is helpful.
Check your answers against the text. The reviewing that takes a little time now will shorten your review time later when you are studying for a test. Remember, if the author took the time to write the questions, they must contain important concepts that are helpful to know and understand. Mouthing the words slows down reading. Try to keep reading.