单选题Bottom blow valves are installed on auxiliary water-tube boilers to （）Aremove suspended and precipitated solids from the boiler waterBcompletely drain the boiler in an emergency situationCprevent hardened scale deposits in the water drumDremove floating impurities from the oily water surface
单选题
Bottom blow valves are installed on auxiliary water-tube boilers to （）
A
remove suspended and precipitated solids from the boiler water
B
completely drain the boiler in an emergency situation
C
prevent hardened scale deposits in the water drum
D
remove floating impurities from the oily water surface
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