单选题A diesel engine should not be operated at low loads for long periods of time because（）Aheavy carbon deposits will buildup on the valves and in the exhaustBfuel dilution is increased at low loadCexhaust valves may be damagedDall of the above
单选题
A diesel engine should not be operated at low loads for long periods of time because（）
A
heavy carbon deposits will buildup on the valves and in the exhaust
B
fuel dilution is increased at low load
C
exhaust valves may be damaged
D
all of the above
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