—Do you know the boy?—_______. He’s Bob’s brother, Bill.

 —I couldn’t get through to you at home last night. You must have gone out then, ________?  — Yes, I went to the cinema.

He seldom has lunch at school, ________? 

-- ________ does it take you to water the flowers?    

There is little doubt in your mind that he is innocent,             ? (2012江苏)