—— Nacy＿＿＿＿＿＿＿＿＿ the letter from her mother.
—— No, she can’t have. The postman hasn’t e yet.
A. can receive
B. can have received
C. must have received
D. must receive
网友回答
A. can receive
B. can have received
(答案→)C. must have received
D. must receive
解析： “must have done”结构，表示对过去发生情况的肯定推测。