A比B多2倍，B比C多它的二分之一，则A∶B∶C=[ ]
A．3∶1∶2
B．2∶1∶3
C．3∶1∶6
D．9∶3∶2
答案：D
若直线y=﹣x+a和直线y=x+b的交点坐标为（m，8），则a+b=（ ）．
—What will you do if it _______ tomorrow?
—I'll stay at home and watch the match on TV. [ ]
A. rain
B. rains
C. will rain
D. is raining
