单项选择题
The boiler feed water check valves are located on the （）
A.feed pump suction line B.hot well C.shell of the feed heater D.feed lines to the boiler
单项选择题 The water level in a steaming auxiliary boiler will always （）
单项选择题 The donkey boiler may be given a bottom blow （）
单项选择题 When steam is being raised on a boiler, the water level will normally （）.
