—Are you free this afternoon?

              —________ I have to meet my brother in the station(车站.

              A. I think so.             B. Yes, I am.          C. I’m afraid not.       D. Right.

--Are you free this afternoon?

--No, I'd like to teach the children        the piano(钢琴)

A. playing      B. what to play C. play      D. how to play

“Are you free this afternoon?” “________ I'll have to look after my uncle.”

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 --- Are you going to the library this afternoon, Kate?

--- Yes, I have to. I ________ READER for two weeks.