无码高清视频|成人自拍视频|欧美成人午夜无码A片秀色直播|草美女视频网站|美女被操网站在线观看

單項(xiàng)選擇題

What could be a result of insufficient lubrication of lifeboat winches and davits?()

A.Moisture accumulation in winch motor damaging the electrical wiring
B.Freezing of gears in cold weather
C.Corroding of sheaves on the davits so they will not rotate
D.All of the above

微信掃碼免費(fèi)搜題