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
