--Must I clean the classroom now, Miss Wang?

--No, you needn’t . It                by Bill.

A. is cleaning     B. should be clean  

C. was cleaned     D. has been cleaned

 - Must I clean the Lable now?

                    - No, you ____.  You may do it later.

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

---Must I clean the floor now?

---__________. It is too dirty.

A. Yes, you needn’t   B. No, you needn’t

C. No, you mustn’t   D. Yes, you must

--Must I clean the yard now，Mom?

-- ________．

A．No，you mustn't          B．No，you needn't         C．No，you shouldn't