I mailed the letter two weeks ago.She_____it.

题目

I mailed the letter two weeks ago.She_____it.
A.must receive
B.can't receive
C.might receive
D.must have received
Nowadays computers _________________ widely in our daily life.
A.use
B.used
C.will use
D.are used

答案

D  must have done 对过去某事的推测,一定是.了,本句意思是她一定是收到了.
D  被动语态,结构是主语+be动词+过去分词,其它三项结构都是错误的,只有D是正确的.