东三区与东九区相比,两地的时差相差[ ]
A.3小时
B.6小时
C.9小时
D.12小时
答案:B
—He should have come to join in the thorough cleaning.
—He _____. I don’t think it was his turn.
A.needn’t have to
B.needn’t have
C.didn’t have to
D.doesn’t need to