—Look! The man at the gate ______ be our headmaster. He is always standing there every morning.
—No, it ______be him. He is holding a meeting in the office now.

—Look! The man at the gate ______ be our headmaster. He is always standing there every morning.

—No, it ______be him. He is holding a meeting in the office now.

A．must, can’t                           B．must, mustn’t

C．can’t, can’t                          D．can’t, mustn’t

---Look. The man at the gate _____ be our headmaster. He is always standing there every morning.

---No. it ____ be him. He is having a meeting in the office now.

1. A.
   must; can’t
2. B.
   must; mustn’t
3. C.
   can’t; can’t
4. D.
   can’t; mustn’t

-- Look! The man at the gate ________ be our headmaster. He is always standing there every morning.

-- No, it ________ be him. He is holding a meeting in the office now.

A. must, can’t        B. must, mustn’t       C. can’t, can’t        D. can’t, mustn’t