单项选择题
A.shaft B.boss C.wheel D.lever
Oil pressure in the lubrication system is（）than the sta...
单项选择题Oil pressure in the lubrication system is（）than the static sea water head to ensure that sea water cannot enter the sterntube in the event of seal failure.
A.higher B.lower C.very higher D.very lower
（）is used to prevent the entry of sea water to the mach...
单项选择题（）is used to prevent the entry of sea water to the machinery space.
A.A special sealing gland B.Propeller C.Tailshaft D.Sterntube bearing
The thrust from the propeller to the hull of the ship i...
单项选择题The thrust from the propeller to the hull of the ship is transferred by（）
A.tie rod B.thrust block C.bedplate of main engine D.frame of main engine
