What were you doing ________ the thief came in?A. when B. while C. after
Do you enjoy __________ on the Internet?
He learns English by ____________ English songs.
It _________ us about two hours _______ that picture last night.
There are so many kinds of radios in the shop. I can’t decide _________.
Father is ill. He wants his doctor to give him _____ about his heart trouble.