Question

A teacher ________also make a mistake if he or she is not careful enough．

1. A.
   must
2. B.
   may
3. C.
   should
4. D.
   has to

Answer 1

B
解析：考查情态动词的运用。must“必须”；may“可能性”；shoud“应该”；has to“不得不”(客观)。