单选题（） fuel oils （） lubricating oils require treatment before passing to the engine.ABoth；andBNeither；norCEither；orDBoth；or
单选题
（） fuel oils （） lubricating oils require treatment before passing to the engine.
A
Both；and
B
Neither；nor
C
Either；or
D
Both；or
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Heavy fuel oils when spilled are ______.A.more harmful to sea life than lighter oilsB.easier to clean up than lighter refined oilsC.less harmful to sea life than lighter oilsD.not a real threat to marine life
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