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單項選擇題

The donkey boiler may be given a bottom blow （）

A.to raise water level
B.only while making steam
C.to remove scum
D.when fire are secured

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單項選擇題

When steam is being raised on a boiler, the water level will normally （）.

A.drop as the boiler warms up
B.rise as the boiler warms up
C.remain unchanged until the boiler is hot enough
D.rise and fall with the steam demand

單項選擇題

The furnace of an oil fired boiler should be （） before the operating burner is lit.

A.filled with water
B.purged
C.cleared of air
D.None of the above is true