单项选择题
A.the bearing had been overheated
B.water was present in the oil
C.the lube oil was not being properly filtered
D.the maximum allowable bearing pressure had been exceeded
单项选择题 Most large, low-speed, main propulsion diesel engines use duplex lube oil strainer to （）
单项选择题 If the cooling water temperature and the lube oil temperature in a diesel engine are too high, the cause can be （）
单项选择题 The reversing cams of some four-stroke/cycle diesel engines are brought into position by （）