—Someone is knocking at the door. Is it Ann?—It _____ be her. She is giving a performance at the theatre now.
I have ____________ homework to do and I’m _______ tired now.
The problem is _________ difficult ________ students can solve them.
---Why don’t you go out to play, Rose? ---I’m afraid I can’t. I have much homework _______.
---Jim, is there __________ in today’s newspaper? ---No,nothing.
When I______ at the hotel,it was very late.