—Is _________ here?—No, John and Bob have asked for a leave.
John ___________ on his friend when he went to Guangzhou last month.
—Paper ___________ wood. We should not waste paper. —I agree. I always use __________ sides of paper.
Are you familiar _____________ the rules of baseball?
In the past, the workers were made __________ 12 hours a day.
—Do you like talking with your friends on the telephone or mobile phone? — ___________. I enjoy chatting on line.