A.60hB.70hC.80hD.90h
A.50~100cmB.100~150cmC.100~200cmD.150~250cm
A.增加斷面B.減小桿件計(jì)算長(zhǎng)度C.增加桿件計(jì)算長(zhǎng)度D.增加桿件質(zhì)量