单项选择题
A.cooling water pump
B.nozzle cooling passages
C.cylinder jackets
D.heat exchanger
单项选择题 Cylinder lubrication oil for low speed main propulsion diesel engines is admitted to each cylinder during （）.
单项选择题 The speed of the camshaft in a two-stroke/cycle diesel engine, running at 950 RPM, is （）.
单项选择题 In a closed diesel engine freshwater cooling system, the amount of coolant flowing through the heat exchanger is controlled by the （）.