She ___________ to Shanghai on business. A. have been B. has gone C. has been
—A number of students________in the dining hall. —Let me count.The number of the students________about 400. A.are;is B.is;are C.are;are
She put back the book she had taken________mistake.
________it rains heavily,they go on working outside.
What________is the most helpful invention?
The dinner didn’t start________all the friends arrived.