单项选择题
Accidental flooding of the engine room bilges by the bilge main is prevented by （）.
A.stop-check valves installed in the bilge manifolds B.using a positive displacement reciprocating bilge pump C.installing eductors in all bilge rose boxes D.installing a swing check before each bilge valve
单项选择题 Zinc rods are installed in the refrigeration system （）.
单项选择题 （）is a series of trials done at sea to determine whether the ship has met the specifications of design, modification, or repair.
单项选择题 A ship designed for carrying goods requiring refrigeration is called （）.
