单项选择题
Which of the following may take place if the clearance of the main bearings are excessive?（）
A.bearing knocks B.dropping of pressure of LO C.noises D.all the above
单项选择题 Which of the following may lead to the engine NOT to start on air?（）
单项选择题 Which of the following may cause that an engine doesnt run on starting air?（）
单项选择题 Which of the following is true about the fuel injection with an ordinary diesel engine?（）
