I don’t know the reason ______ you were absent from the meeting, but I’m sure

that someone will tell me the reason ______ you haven’t told me.

　　 A. why, that　 B. that, why　 C. because, which　 D. of which, that

I don’t know the reason _________ you were absent from the meeting, but I’m sure it’s for some reason ________ you don’t want people to know.

A. why; that　　　 B. that; why　　 　C. that; which　　 D. which; what

I don't know the reason __________ you were absent from the meeting, but I'm sure that someone will tell me the reason _________ you haven't told me.

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