单项选择题
A.the use of a poor quality oil
B.the deterioration of its properties
C.the formation of deposits
D.the reduction in heat transfer ability
单项选择题 Large crosshead type engine generally has two lubrication systems, a function performed only by crankcase oil system is()
单项选择题 Large crosshead type engine generally has two lubrication systems, a function performed only by cylinder oil system is()
单项选择题 In some diesel engine designs,()the injection of cylinder oil is timed to impinge when the piston and only impinge on()