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 It's impolite to cut in when two persons are holding a conversation
A leave B talk loudly
C stand up D interrupt
答案：11. B 12. B 13. A 14. C 15. D