( )Did you do ? A. Yes, I do. B. Yes, he does. C. Yes, I did.
()What did you_____ on the earth? A. buy B. buying C. bought
()They _____going to different schools. A. is B. are C. do
()I _____the name of a friend. A. write B. writing C. am write
()There is _____ big bird in the tree. A. a B. an C. the
()Why are you _____ ? A. laugh B. laughing C. sing