---George, how can you prove the earth is round ?--- I can’t, sir. ______ , I never said it was.
Will you stay at home ____ Sunday morning?
—Mum, _________ I play football? —Yes, you can. But you should finish your homework first.
It’s snowing all day, so mybrother ______ stay at home. A.must B.have to C must to D.has to
The two boys are fighting _______ each other.
When will the Greens arrive _______ Nanjing.