“You didn’t go to the movie with them, did you?”“___________Because I was very busy”

—I told you not to be absent from the class meeting again，________I ?—Sorry，I am afraid that I forgot it．

His sister’s never been to the Summer Palace, _______?

—Oh, you have a headache and a cough. __________ have you been like this?— Two days.

I really don’t know ______________.