There is usually one important subject missing from most schools’ (21)______. Very few students are taught (22)______ to organize their learning, and how to make the best use of their time. Let’s take some simple examples. Do you know how to look (23) ______ words in a dictionary, and do you understand all the information the dictionary contains? Can you make notes quickly, and can you understand them afterwards? For some reasons, (24)______ schools give learners no help with these matters. Teachers ask students to memorise pages from books, or tell them to write ten pages, but don’t explain how to do it. Learning by (25) ______ can be useful, but it is more important to have a genuine understanding of a subject. You can waste (26)______of time memorizing books, without understanding anything about the subject! 17. A. semesters B. terms C. timetables D. years 18. A. what B. where C. how D. why 19. A. up B. at C. after D. for 20. A. every B. no C. much D. many 21. A. head B. heart C. mind D. work 22. A. some B. a lot C. a lots D. a few