第二部分 知识运用（共两节，满分45分）
第一节 单项选择 （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 considered unwise to give a child___________ her or she wants。
A．however B. Whatever C. whichever D. whenever
答案是B
21. It is reported that many a poultry-trading centre _________down at present in the flu-stricken areas in Southeast China.
A. are being closed B. were being closed
C. was being closed D. is being closed
