21. It is the most instructive lecture that I _______ since I came to this school.
A. attended B. had attended
C.am attending D. have attended
22. In Africa, educational costs are very low for those who are_______enough to get into universities.
A. successful B. fortunate C. proper D. happy
23. .My father had longed to play music since childhood, but his family was poor and couldn’t _____ lessons.
A. miss B. afford C. select D. understand
24.—How was your recent trip to Sichuan?
—I've never had ________ one before.
A. a pleasant B. a more pleasant
C. a most pleasant D. the most pleasant
