A.≥梯段寬度 B.≥梯段水平投影長度 C.≤梯段寬度 D.≤梯段水平投影長度
A.900mm B.1100mm C.1200mm D.1400mm
A.[0.5+(0.1~0.2)]m B.[0.55+(0.1~0.2)]m C.[0.5+(0~0.15)]m D.[0.55+(0~0.15)]m