A.熔焊 B.螺栓 C.絲接 D.套接 E.法蘭
A.40m-50mB.50m-60mC.60m-70mD.70m-80mE.70m-100m
A.15m-20m B.20m-30m C.25m-30m D.30m-35m E.35m-45m