You may get lost easily in big cities like Beijing        you have a map or a guide.

—Do you know       ? —I’m not sure, maybe he is an artist.

She __________ be here. I saw her come in.

---Excuse me, may I take the magazine away? ---No, you ______. You ______ only read it here.

According to the new traffic laws, people ______ drive after drinking wine or beer.

He has poor _______, so he can’t see the words on the blackboard clearly.

The factory ______ its waste into the river, but now it deals with the waste in a new way.

The art exhibition is really worth _______，and you’re sure to learn lot from it. 

For everyone’s safety，we _______ a1ways remember the law against driving after drinking.

Mr Chen __________ his mobile phone to the shop because it can’t work at all.

He used to _______ in a village, but now he has been used to _______ in the big city.

--- 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.

—Look at the sign. You_____ fish here.—Sorry, I didn’t know.

—Must I finish the exercise this afternoon?—Yes, you ______, but you ______ finish it now.

J K Rowling jumps farther than ______ in her class.

— Congratulations! You’ve got the first prize in the English Contest.—_____ it be true? It’s unbelievable!

---Do you know why Anna hasn’t come to school today? ---I’m not sure. She _______ be ill.

– Whose ping pong bat is this? -- I’m not sure. I think it ______be Tom’s.

--Listen! Someone is knocking at the door. Who _____it be?---It_____be Tom. He phoned to visit me this evening.

-Listen! Is Mary playing the piano in the room?  --No. It ________ be Mary. She has gone to Hong Kong.