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。