单项选择题
Which of the following will 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 will be the function of lubricating oil used in marine engines?（）
单项选择题 Which of the following may take place if the clearance of the main bearings are excessive?（）
单项选择题 Which of the following may lead to the engine NOT to start on air?（）
