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
单项选择题 For proper operation, auxiliary boiler feed water must have which of the following characteristics?（）
单项选择题 If a four-stroke/cycle diesel engine is running at 1550 RPM, the speed of the camshaft will be（）.
单项选择题 An indication of a diesel engine air intake being partially clogged, is （）.
