单项选择题
In a large, slow-speed, main propulsion diesel engine, which of the parts listed is under tension when the engine is running?（）
A.Bed plate B.Column C.Entablature D.Tie rod
单项选择题 The color of the exhaust from a diesel engine should be （）
单项选择题 Scavenging in a four-stroke/cycle diesel engine occurs during the （）.
单项选择题 The device allowing for the change in volume of the cooling water in a propulsion diesel engine closed cooling system is the （）.
