Standby or emergency diesel generator day tanks should always be kept full to reduce the possibility of（）

A.a cracked cylinder head
B.a leaky cylinder head gasket
C.a cracked cylinder liner
D.any of the above

A.Ensure proper cylinder lube oil flow
B.Open all air space drain cocks
C.Open all indicator valves
D.all of the above

A.allow impurities to settle out of the fuel
B.allow air to escape from the fuel
C.make fuel available for immediate use
D.all of the above