It is so late. Our son be back .
Don’t worry . I dare say he have some extra work to do.
A. can ; must
B. will ; might
C. should ; must
D. must ; may
网友回答
A. can ; must
(答案→)B. will ; might
C. should ; must
D. must ; may
解析：考查情态动词。Will在这里表示推测，可能，想必，might have done,表示对过去可能性的推测。句意：如此的晚了，我们儿子这时候会回来的。别担心，我敢说他可能有一些额外的工作要做。所以选B。