The ground is wet all over, so I’m sure it must have rained last night, ?
A. wasn’t it
B. didn’t it
C. isn’t it
D. doesn’t it
网友回答
A. wasn’t it
(答案→)B. didn’t it
C. isn’t it
D. doesn’t it
解析：本题考查反义疑问句。I’m sure it must have rained last night, ?
主句主语为I，所以对从句反问，it must have rained last night，有具体的过去时间last night，所以用一般过去式didn’t it 。如果没有具体的过去时间，则用完成时hasn’t it。所以选B。