How many teachers are there in your school? —I’m not sure about it. Maybe.

Can you tell me ___ it is from here to the history museum?— It’s about half an hour’s walk.

Jack and Tom reached Beijing ______ May 16, 2008.[ ]

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

We’ll have dinner at Qianxilong Restaurant, which is famous ________ its food.[ ]