问题
Often, when he _________ something that ___________ him, he wasted his time drawing some little pictures. [ ]
A: should be doing; gave
B: should have been doing; was given
C: should do; was given
D: should have been doing; had given
B: should have been doing; was given
C: should do; was given
D: should have been doing; had given
正确答案是：
