一个三角形的一条边长9厘米,按一定的比例缩小后是3厘米,这个三角形的缩小比例是[ ]
A.3:1
B.1:3
C.6:1
答案:B
I arrived late; I _____ the road to be so icy.
A.wouldn't expect
B.haven't expected
C.hadn't expected
D.wasn't expecting
水泵按泵轴的位置分为()和()两种。