Will you be back _____ five in the afternoon? — I am not sure, maybe later than that.

Mr. Smith __________ is smoking is looking for________ she lost yesterday. [ ]

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

Guess,how much does it cost? —I think it costs_______15 and 20 dollars.[ ]

I preferred _______the long jump rather than ________ in the relay race in the school sports games.