--Who is singing in the next room?

--         must be Marie．

A．It                        B．She                     C．This                             D．There

--Who is singing in the next room?

--________ must be Marie.

1. A.
   It
2. B.
   She
3. C.
   This
4. D.
   There

—Who is singing in the next room?　

— It _____ be Lucy. She has gone to Hong Kong.

A. can’t　　　　 　　　　　 B. must　　　　 C. may not　　　　　 D. needn’t