单项选择题
A.maintain alignment when the ship’s hull is working in heavy seas
B.ensure engine vibrations correspond to the natural frequency of the hull
C.permit the engine to expand away from the driven equipment as the engine heats up and expands
D.maintain engine thrust bearing clearances
单项选择题 Some medium and high-speed diesel engines require reduction gear units to provide a useful propeller speedIn most reduction gears, the bull gear（）
单项选择题 A four-stroke cycle, turbocharged, 1000 horsepower diesel engine has been operating under loadThe load suddenly increases, causing excessive black exhaust smoke, and a rapid rise in the lube oil temperatureIn response to this condition, you should:（）
单项选择题 Which of the following procedures should be carried out when a large, low-speed, diesel engine is operated with one cylinder secured?（）