—Is this your ruler?—Yes, it’s ________
—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.
My mother arrives late _______ work because of the heavy rain.