第一节 单项填空 (共15小题；每小题1分，满分15分)
从A、B、C、D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
例：It is generally unwise to give a child ______ he or she wants
A. however B. whatever C. whichever D. whenever
答案是B。
21. I think ______ information of this kind is help when you look for a job.
A.不填; a B. the; a C. an; a D. the; 不填
22. -- When do you need to pay the balance?
-- ______ December 31.
A. In B. By C. During D. Within
