【题目】－Mary，how did your Math test go?
－I had thought I _________，but in fact I came in the top 10 in my class.
A． should have failed
B． couldn’t have failed
C． have failed
D． shouldn’t have failed
在线课程【答案】A
【解析】should have done的意思是：本应该做（但此结构暗示了实际上没有完成），根据句子的意思可知此题应选A。