单项选择题
A.air filtration is inadequate
B.engine coolant leaking into the lube oil
C.fuel oil is leaking into the lube oil
D.the piston rings are excessively worn
单项选择题 When fuel oil is accidentally missed with lube oil which of the following processes can be used to separate them?（） Ⅰ.filtering Ⅱ.settling
单项选择题 A lube oil sample taken from the main engine lube oil system has dark yellow opaque color.This is the result of （）
单项选择题 When you are transferring fuel oil to the setting tanks, precautions to be observed should include （）