Question

Mr．Costa is on time for everything．How ________ it be that he missed his flight？

1. A.
   should
2. B.
   can
3. C.
   may
4. D.
   dare

Answer 1

B
can和may都可以用来表示猜测，解释为“可能”。但是，通常情况下，may只能用在肯定句中，而can则多用于表示疑问和否定的语气，How can it be that…表示“……怎么可能呢?”