A.1:5,≥3m B.1:12,≥1.20m C.1:8,≥1.5m D.1:6,≥2.5m
A.≥3m B.≥2m C.≥1.5m D.≥2.5m
A.粗糙,防滑 B.平整,光滑 C.坑洼,粗糙 D.防滑,粗糙