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：
