9 If wool is put into hot water， it tends to shrink.
A disappear
B expand
C break
D contract
10 The train came to an abrupt stop， making us wonder where we were
A an uncertain
B a slow
C an unexpected
D a smooth
11 Almost all economists agree that nations， gain by trading with one another.
A work
B profit
C rely
D prove
12 The conference explored the possibility of closer trade links.
A denied
B investigated
C stressed
D created
13 The chemical is deadly to rats but safe to cattle
A fatal
B hateful
C good
D useful
14 During his lifetime he was able to accumulate quite a fortune.
A control
B spend
C collect
D exchange
15 Its impolite to cut in when two persons are holding a conversation
A leave
B talk loudly
C stand up
D interrupt
答案：1. C 2. C 3. C 4. C 5. A6. C 7. D 8. B 9. D 10. C11. B 12. B 13. A 14. C 15. D