—Why aren’t they here yet?—They the bus.A. can have missedB. must be late for C. may have

问题补充：

—Why aren’t they here yet?

—They the bus.

A. can have missed

B. must be late for

C. may have missed

D. might be late for

答案：

A. can have missed

B. must be late for

(答案→)C. may have missed

D. might be late for

解析：他们未何还未到？可能是未赶上汽车。表示对过去事实的猜测。故选C。