---Your answer _________ right.--- Really? But I’m not quite sure. __________ yours is right.
How can you study in the living room when other people are watching TV? I think you need a _______ place.
--- Mr. Green, I think physics is too difficult for me. ---Tom, work hard, _______ you’ll find it not as difficult.
--- Listen! David is talking happily with his mother in the next room. --- It ______ be his mother. She has gone to Yunnan to be a volunteer doctor.
--- Have you got the e-mail I sent you this morning? --- I found an e-mail in my mailbox, but it wasn’t ______ you.
—Would you please help me with my drawing? —_____. You can come to my workroom every Saturday.