单项选择题
A.Flash point improvers
B.Pour point improvers
C.Inhibitors
D.Foam suppressors
单项选择题 Which of the following characteristic of lube oil helps to reduce the amount of deposits in the piston ring belt during the combustion process in a diesel engine?()
单项选择题 A diesel engine exposed to widely varying ambient temperatures should use to a lubricating oil with ()
单项选择题 The Total Base Number (TBN) value of diesel engine lube oil refers to its ability to ()