单项选择题
A.at any time
B.only after the engine room control station is switched to ‘bridge control’
C.whenever the secondary station is switched to ‘bridge control’
D.whenever the engine side control station is switched to ‘bridge control’
单项选择题 The camshaft drive is designed to maintain proper camshaft speed relative to crankshaft speedIn maintaining this relationship, the camshaft drive causes the camshaft to rotate at（）
单项选择题 The abbreviation ‘M/E’ is used to represent the（）
单项选择题 Where tanks are arranged for either oil or ballast （） must be fitted in the pipe so that only the ballast main or the oil transfer main connected to the tank.