I don’t know ______ with this problem. It’s too hard.
—are you going to Shanghai? —I’m taking the plane.
—Which is the biggest number of the four? —.
What did Mr.Smith do before he came to China? —He in a car factory.
—Hello! May I speak to Lucy,please? —Sorry,I’m afraid you have the wrong .
—Mike,is this Tom’s pencil? —Oh,yes,it is !