Every minute is made full use of at our lessons.A. to workB. workingC. having workedD. be

问题补充：

Every minute is made full use of at our lessons.

A. to work

B. working

C. having worked

D. being worked

答案：

(答案→)A. to work

B. working

C. having worked

D. being worked

解析：此题中of 的宾语实际是Every minute，如果把它变成主动式，答案就容易见到了。