11.These are the motives for doing it.
A reasons
B excuses
C answers
D replies
12.The river widens considerably as it begins to turn west.
A extends
B stretches
C broadens
D bends
13.Many economists have given in to the fatal lure of mathematics.
A error
B puzzle
C attraction
D contradiction
14.With immense relief I stopped running.
A no
B little
C scarce
D enormous
15.A great deal has been done to remedy the situation.
A maintain
B improve
C preserve
D protect
參考答案：11. A 12. C 13. C 14. D 15. B