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 （）.

单项选择题 Mechanical lubricators for diesel engine cylinders are usually small reciprocating pumps which are （）.