A.1/2 B.1/3 C.1/4 D.1/2~1/4
A.中間加桿吊起 B.上部兩端點(diǎn)吊起 C.下部兩端點(diǎn)吊起 D.底部兩端頭槽鋼下兜吊
A.1.2m B.1.4m C.1.6m D.1.8m