从480里连续减去多少个5，结果是0？[ ]
A.475
B.95
C.485
D.96
答案：D
I’m sorry I took your backpack______ .
A．because mistake
B．with mistake
C．by mistake
D．by mistakes
桥梁墩上桥支座为两个固定支座时，梁缝处轨枕间距宜设为（）
A、650mm
B、630mm
C、635mm
D、640mm
