单项选择题
If an operating auxiliary boiler has a water pH reading of 7, you should （）.
A.bottom blow the boiler B.treat the water with caustic soda C.treat the water with chemical scavengers D.reduce the water alkalinity to recommended readings
单项选择题 Generating tubes in waste heat boilers are finned to （）.
单项选择题 Directional intake ports in diesel engines are used to （）.
单项选择题 Mist detectors used on large low-speed main propulsion diesel engines monitor and check for the presence of （）.
