第一节、单项选择（共15小题，每小题1分，满分15分）
21. Chinese Vice-Premier called on Thursday for _____ all-out effort to ensure _____ food and drug safety.
A.an; a B. an;\ C. the; the D. \;the
22. ---This is my book.
---_____________ It has my name on it.
A. Here you are! B. How do you find it?
C. It’s hard to say. D. You must be joking!
