18. She murmured something and blushed as if a secret had been ?____?.?
A. imposed
B. exposed
C. removed
D. renewed?
19. Your service is entirely ?____? , not compulsory.?
A. selective
B. optional
C. voluntary
D. reluctant?
20. Their distribution is also ?____?, sometimes, widely spaced, in places, closely packed together.?
A. various
B. alternative
C. variable
D. conventional?
21. Food and drink are good and desirable, but their ?____?can cause serious health and mental problems.?
A. effect
B. abuse
C. custom
D. usage?
22. I called on him the morning after our arrival, and was ?____?with his gay, precise manner and obvious power of decision.?
A. inclined
B. implied?
C. impressed
D. illustrated?
23. The trade agreement between the two countries will ?____?next year.?
A. adjoin
B. expire
C. boost
D. concede?
24. Two boys were caught smoking at school but the headmaster let them ?____? with a warning.?
A. off
B. down
C. out
D. alone?
25. Advertising costs are no longer in reasonable ?____?to the total cost of the product.?
A. testimony
B. relationship
C. proportion
D. legislation