A.≥1.20m B.≥1.70m C.≥1.60m D.≥1.30m
A.≥1.50m B.≥1.70m C.≥1.60m D.≥1.30m
A.1:5,≥3.0m B.1:20,≥1.50m C.1:8,≥1.50m D.1:6,≥2.50m