单选题Lubricating systems for diesel engines are usually designed to initially provide lube oil to the engine （）Acamshaft beatingsBmain bearingsCpiston crownsDcylinder walls
单选题
Lubricating systems for diesel engines are usually designed to initially provide lube oil to the engine （）
A
camshaft beatings
B
main bearings
C
piston crowns
D
cylinder walls
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