A.1 B.2 C.3 D.7
A.30 B.60 C.90 D.120
A.踏面擦傷長度<30mm，深度<0.5mm B.踏面擦傷長度<60mm，深度<0.5mm C.踏面擦傷長度≤30mm，深度≤1mm D.踏面擦傷長度≤60mm，深度≤1mm
