21: A. entertain B. similar C. carefully D. history

20: A. attract B. verbal C. signal D. social

19: A. category B. accompany C. experience D. compulsory

18: A. polite B. roommate C. diverse D. apply

17: A. assistance B. appearance C. position D. confidence

16: A. parent B. attempt C. women D. dinner

15: A. lemon B. physics C. decade D. decay

14: A. parallel B. dependent C. educate D. primary

13: A. decent B. reserve C. confide D. appeal

12: A. advocate B. diversity C. employment D. decision