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