— I can’t get through to the general manager’s office.
—The line is busy. Someone ________ the telephone.

You ______ your coffee before it turns cold.

Students ought ______ the truth.

The flowers ________ every day, or they will die.

--- Can you spell your name, please?
--- Yes, I _________.

---Mum, I’m stressed out.
--- I think you ____ listen to some music..

–Can you speak French?
--Sorry, I______.

— Must we finish our homework today?
— No, you ________.
A．can’t            B．mustn’t          C．don’t have to

This case is too heavy. Could you _____ me a favor?
A．to do               B．doing           C．do

Mr Black   be at home because she called me from England just now.