A.0.2 B.0.3 C.0.4 D.0.5
A.宜 B.可 C.应 D.必须
A.8.0~9.0 B.4.0~8.0 C.3.0~6.0 D.9.0~10.0
A.1.5m B.1.2m C.1.0m D.0.8m
A.50m B.75m C.100m D.150m