As we all know, food is very important in our life. Everyone in the world needs to _______ 21 well if he or she wants to have a strong body. Our minds also need a kind of food. This kind of food is _______ 22. Knowledge is the information, understanding and skills that we gain through education or experience. We begin to get knowledge even _______ 23 we are very young. Small children are very interested _______ 24 everything that is around them. They learn _______ 25 when they are watching and listening. When they are getting older, they begin to _______ 26 books that they like, such as storybooks and popular science books. When they find something new, they like to ask questions and try to _______ 27 answers. What is the best way _______ 28 knowledge? If we learn by ourselves, we will get _______ 29 knowledge. If we _______ 30 get answers from others and do not ask why, we will never learn well. When we study in the right way, we will learn more and understand better. So let’s take action from now on.21. A. sleep B. match C. drink D. eat22. A. sport B. exercise C. knowledge D. meat23. A. until B. when C. after D. if24. A. in B. on C. off D. at25. A. everything B. something C. nothing D. anything26. A. lend B. revise C. read D. write27. A. try out B. find out C. break out D. turn out28. A. to get B. getting C. get D. having got29. A. little B. few C. many D. much30. A. rarely B. always C. seldom D. sometimes