按要求改写句子，每空格限填一词。

Perhaps the young man is our new teacher.（保持原意不变）

The young man ______ ______ our new teacher.

The tall man over there is our new English teacher, _________?

1. A.
   is he
2. B.
   is there
3. C.
   isn’t he
4. D.
   isn’t there

The old man ___ a blue sweater is our new headmaster.

– Who is ______ man with glasses?
-- Oh, he’s our new English teacher, Mr. Li.

—Who’s that man under the tree? Is it Mr Black, our new English teacher?

—It_______ be. Mr Black has gone to Shanghai for a holiday.

   A. mustn’t                                              B. can’t                                                C. needn’t