Question

—Did Mary come to the party?

—I don’t know.She______while I was out.

A.may have come                       B.must have come

C.might come                            D.could come

Answer 1

A

解析:

此句考查情态动词和完成形式连用。由语境可知是对过去的推测，应用完成形式。 I don’t know 表明答话者没有把握，故选A项。