单项选择题
A.10 B.7 C.4 D.1
If over a period of weeks the air-box pressure of a tur...
单项选择题If over a period of weeks the air-box pressure of a turbo-charged, diesel engine, operating at full load, appears to be dropping off, the cause can be （）.
A.open air-box drains B.loss of cooling water to the diffuser C.gradual fouling of the air filters D.improperly timed exhaust valves
The most common cause of scale formation in an auxiliar...
单项选择题The most common cause of scale formation in an auxiliary boiler is （）
A.concentrations of calcium sulfate in the boiler water B.fuel oil in the feed water C.improper treatment of the feed water with calcium sulfate D.excessive feed water alkalinity
For proper operation, auxiliary boiler feed water must ...
单项选择题For proper operation, auxiliary boiler feed water must have which of the following characteristics?（）
A.High oxygen concentration B.Low pH C.Proper alkalinity D.All of the above
