单项选择题
A.70mm~120mm B.60mm~130mm C.60mm~120mm D.90mm~150mm
A.垫圈、弹垫、螺栓;45 B.垫圈、弹垫、螺栓;25 C.弹垫、垫圈、螺栓;45 D.弹垫、垫圈、螺栓;25
A.10m B.20m C.30m D.40m