二、单项选择（本题有10小题，每小题0.5分，共10分）
11. – We should take much exercise to keep healthy.
--_________
A. Why not? B. Really?
C. I can’t agree with you. D. Absolutely correct.
12. It is generally believed that constant reading and comprehending can ______ our mental ability of comprehension while physical exercise can help build up our body.
A. stress B. effect C. strengthen D. decide
