问题
选择题
When Madam Cuirie did the science experiement again, she was more careful where she _____ a mistake.
A.made
B.has made
C.was making
D.had made
答案
答案:D
由句意知“犯错误”是发生在“was more careful”之前,故用过去完成时。
【标签】动词时态