Onereasonthatwehaven’thadhisletteristhathe             ...

问题详情：

One reason that we haven’t had his letter is that he               it to our old address by mistake.

A. might send                                 B. should have sent

C. should send                               D. may have sent

【回答】

D  

知识点：虚拟语气与情态动词

题型：选择题