单项选择题
When an auxiliary boiler is panting and emitting black smoke, you should （）.
A.increase the fuel oil temperature B.decrease the fuel oil temperature C.decrease the fuel oil supply pressure D.increase the air supply
单项选择题 With regards to a diesel engine crankcase explosion, the most violent is the（） (1) primary explosion (2) secondary explosion
单项选择题 Waterside scale in a fire-tube boiler may cause （）.
单项选择题 The maximum pressure developed by a waste heat boiler is determined by the main engine exhaust （）.
