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單項(xiàng)選擇題

At normal sea going, we use （） instead of donkey boiler.

A.a heater
B.a pre-heater
C.an exhaust gas boiler
D.the coal burning boiler

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單項(xiàng)選擇題

The soot blowers are operating in the oil fuel boiler the air/fuel ratio must （） throughout the action, and blowers greased after use.

A.be increased
B.be decreased
C.remain constant
D.either be increased or remain constant

單項(xiàng)選擇題

Water evaporates or steam condenses at the saturation temperature, which depends upon the pressure, the higher the pressure （） the saturation temperature.

A.the more
B.the higher
C.the lower
D.the highest

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