13.______you choose, make sure that it is a good one.
A. What B. Wherever C. Whichever D. Which
14.He suggested the sports meet be _______because of the bad weather.
A. put away B. put up C. put down D. put off
15.I didn’t manage to work out the problem _______the teacher had explained how.
A. until B. unless C. when D. before
Keys:
1—10 ABDDD CBCCB 11—15 BBCDA
责任编辑：sealion1986
