二、单项选择：（共20小题，每小题0.5分，共10分）
11. Knowing how to give first aid really ______ in case of emergency. It can save lives.
A. makes difference B. has a difference C. makes a difference D. makes the difference
12. — How you are looking!
— I’m really terrible! It has been one month ______ I ______.
A. since; fell ill B. before; became ill C. when; fell ill D. as; was ill
13. Who else can I depend on for help, if not ______?
A. he B. himself C. his D. him
14. We must work hard to _____ a good knowledge of English.
A. earn B. acquire C. give D. achieve
15. — What do you think of the film “Avatar”?
— ______ it with “2010”, I have ______ the former.
A. Compare, preference for B. Compared, a preference with
C. Comparing, preference with D. Comparing, a preference for
