單項選擇題

The water level in a steaming auxiliary boiler will always （）

A.rise when the steam pressure is increased
B.remain constant as long as the feed pump operates
C.fall when the steam pressure is decreased
D.vary as the steam demand changes

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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

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