单项选择题
A.plating forming the engine room tank top
B.doubler plating installed over the flat keel plate
C.a watertight boundary formed by the inner bottom
D.compartments between the inner and outer bottoms
单项选择题 The lowest temperature at which fuel combustion becomes self-sustaining in the presence of a source of ignition, is defined as the （）
单项选择题 Thermostatic steam pressure reducing valves are used in the fuel oil service system to control the（）
单项选择题 The construction of the main propulsion engine lube oil sump should （）