A.點(diǎn)接觸 B.線接觸 C.面接觸
A.制動(dòng)器應(yīng)是隔爆型,起升機(jī)構(gòu)應(yīng)有兩個(gè)制動(dòng)器 B.當(dāng)防爆級(jí)別為ⅡC時(shí),電纜滑車的牽引線應(yīng)采用不銹鋼鋼絲繩 C.當(dāng)防爆級(jí)別為ⅡC時(shí),吊鉤應(yīng)采取能防止撞擊或摩擦而產(chǎn)生危險(xiǎn)火花的措施 D.起重機(jī)宜采用開(kāi)式齒輪傳動(dòng)
A.3.5 B.4 C.4.5 D.5