单项选择题
Whilst the engine is turning, check to see that no water is leaking into the crankcase, scavenge air belt, or from （）.
A.exhaust valves B.starting valves C.fuel valves D.the indicator cocks
单项选择题 While engine is in operation the piston moves up and down, thus causing the rotation of the （）.
单项选择题 Which of the following would cause a diesel to have black smoke?（）
单项选择题 Which of the following will take place if the clearance of the main bearings are excessive?（）
