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單項(xiàng)選擇題

The boiler water alkalinity in a coil-type auxiliary boiler should be maintained at the pH recommended by the boiler manufacturer to（）

A.precipitate silica from solution
B.reduce corrosion in the heating coil
C.prevent clogging and erosion in the coil
D.maintain zero water hardness

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單項(xiàng)選擇題

Diesel engine waste heat boiler construction is usually of the fire-tube or（）

A.cyclone furnace boiler type
B.dry back boiler type
C.water-tube type
D.critical circulation boiler type

單項(xiàng)選擇題

Auxiliary boilers are divided into several classifications, one of which is（）

A.fire-tube controlled circulation
B.fire-tube supercritical circulation
C.water-tube natural circulation
D.water-tube express circulation

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