―Can he take charge of the computer company?
 ―I’m afraid it’s        his ability.
      A. beyond             B. within               C. of                    D. to

 ---Is Jack on duty today?

    ---It ________ be him. It's his turn tomorrow.

    A. mustn't         B. won't            C. can't            D. needn't

It’s his laziness that ________ his failure in the last exam.

A. resulted from         B. resulted in           C. led into        D. brought in

―Is Jack on duty today?

   ―It       be him. It’s his turn tomorrow.

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

—Is Jack on duty today?

—It ________ be him; it's his turn tomorrow.

A．mustn't 

B．won't

C．can't 

D．needn't