单项选择题
A.110mm B.120mm C.140mm D.150mm
A.0.9m高的临时护栏 B.0.9m高的永久护栏 C.1.2m高的临时护栏 D.1.2m高的永久护栏
A.0.3m~0.4m B.0.4m~0.5m C.0.5m~0.6m D.0.8m以上