21. What I want to do most is to have_____ quite interesting book, and ___ time to enjoy it.
A. the; the B. a; the C. /; the D. a; /
22. I went to see my friends the Smiths,_____ children I used to look after when they were small.
A. who B. whom C. whose D. when
23. Not until _____ to help _____do it.
A. his friend offered; he could B. did his friend offer; could he
C. did his friend offer; he could D. his friend offered; could he