21.Miss Chen can show you around        mountain, because she has          good knowledge of it.
A. the; a              B. a; the               C. a; a            D. the; ∕
22.Their country has plenty of oil,        ours has none.
A. when             B. while               C. and            D. so
23. Granny White lives         in a faraway village, but she doesn’t feel        at all.
A. alone; lonely       B. lonely; lonely        C. lonely; alone     D. alone; alone
24. If you don’t go to school,           I.
A. nor do            B. so will              C. so do           D. neither shall
25. A number of students      absent from the meeting and the number of them     surprising.
 A. were; was         B. was; were           C. was; was        D. were; were