单项选择题
A.defective solenoid valve
B.dirty fuel nozzle
C.grounded high tension lead
D.faulty ignition cable connector
单项选择题 A firebox explosion in an automatically fired auxiliary boiler may be the result of （）
单项选择题 The diesel engine exhaust gas bypass, as fitted with some waste heat boilers, is installed to （）
单项选择题 The fuel oil supply system to an automatic auxiliary boiler, will automatically shutdown if the boiler （）