Time should be made good use of our lessons well.
A. learning
B. learned
C. to learn
D. having learned
网友回答
A. learning
B. learned
(答案→)C. to learn
D. having learned
解析：
考查的是不定式做目的状语。此句是利用被动结构设置陷阱。转化为主动态是：(We) should make good use of time to learn our lessons well。