15-50mm,50% B.10~40mm,40% C.15-50mm,40% D.10-40mm,50%
A.40mm,40% B.50mm,40% C.50mm,50% D.40mm,50%
油水艙檢修完畢后,應(yīng)()。 ①檢查艙內(nèi)是否清潔干凈;②是否有遺漏工具;③封人孔蓋時(shí)確保艙內(nèi)無(wú)人;④保證人孔蓋水密。
A.①②③對(duì) B.②③④對(duì) C.①③④對(duì) D.①②③④對(duì)