lubricants

A well－lubricated bearing surface always appears__________.

Lubricating oil used in a diesel engine serves to _________.

_______ diesel engines generally have two systems of lubrication: a total loss system feeding and a circulating system lubricating the running gear and cooling the pistons.

Which of the listed cylinder liner surface conditions indicates proper lubrication？A.Dull

Sludge may form. in the lubricating oil crankcase of a reciprocating air conditioning comp

（)provides strength and storage space for fuel，lubricating oil，fresh water，salt（ballast)wa