I think it must be a dog, but he thinks it ________ be a dog.

[　　]

-Where's our English teacher?

-He ______ in the library.

A.mustn't is　　　　

B.maybe

C.can　　　　

D.must be

---The coat with Yao Ming’s picture _________ Tom’s. He likes him very much.

--- No, it ___________ be like his. He dislikes black colour.

A. must be; mustn’t B. may be; may not C. must be; can’t D. maybe; can’t

One night, Mary heard some big  36_  noise.  “Doh, Doh, …” It  37   for a few minutes.  Mary went out of her bedroom to search everywhere.  Her parents were sleeping and there were no   38  people in the house.  Mary   39 _ to her bedroom.

Mary heard the noise again.  She thought, “Is it a cat?  Mike has a cat.  But cats miaow.  They don’t make such noise.”

“Maybe it’s a bird   40   around and looking for a place to rest.  No!  That doesn’t make any noise.”

Maybe it’s the whisper of my parents.  They _41   be   42   in their room.  But that noise wasn’t a whisper at all.”

Mary went to bed again but she heard the noise again. She was   43_   and fell  44_    her bed. Her legs were   45_   and she could not climb up any more.