问题补充:
Mary her homework last night because she was ill.
A. didn’t
B. didn’t do
C. doesn’t
D. doesn’t do
答案:
A. didn’t
(答案→)B. didn’t do
C. doesn’t
D. doesn’t do
解析:句意:Mary昨晚没有做她的家庭作业,因为她生病了。句中有时间状语last night,所以我们可以知道这说的是过去的事,应该用一般过去时,否定句用助动词did,做作业是do one’s homework,故选B。