16. My sister's professor had her__ her paper many times before presenting it to the committee.
　　A. rewrite
　　B. to rewrite
　　C. rewrote
　　D. rewriting
　　17. The locals, all of whose homes __ by the flood, received help from the Red Cross.
　　A. damaged
　　B. had been damaged
　　C. damaging
　　D. to damage
　　18. When people get unemployed, what is often worse than lack of wages is __
　　A. poverty
　　B. laziness
　　C. idleness
　　D. inability
　　19. English serves as a common tongue in countries__ people speak many different languages.
　　A. which
　　B. why
　　C. where
　　D. that
　　20. In recent years special attention has been paid__ developing the students' productive skills.
　　A. over
　　B. to
　　C. on
　　D. in
　　21. A thirty-minute-call anywhere in the United States costs __ than a dollar when you dial it yourself.
　　A. least
　　B. less
　　C. few
　　D. little
　　22. I wish I＿＿longer this morning, but I had to get up and come to class.
　　A. could have slept
　　B. slept
　　C. might have slept
　　D. have slept
　　23. If you don't know the meaning of the word, you simply can＿＿a dictionary.
　　A. make out
　　B. go over
　　C. look up
　　D. refer to
　　24. A good writing＿＿clear organization and choices of words.
　　A. calls on
　　B. calls for
　　C. calls up
　　D. calls off
　　25. It is hard to avoid mistakes.＿＿you correct them carefully, it will be all right.
　　A. In the case
　　B. As long as
　　C. Although
　　D. Despite