单项选择题
A.Copper B.Copper and carbon C.Carbon D.Bronze
For the proper control of the air temperature in an air...
单项选择题For the proper control of the air temperature in an air conditioning system using chilled water circulation, which of the listed conditions should remain constant regardless of load changes?（）
A.Chilled water system supply temperature B.Chilled water system return temperature C.Compressor discharge temperature D.Compressor suction pressure
The flame safeguard control system of a large automatic...
单项选择题The flame safeguard control system of a large automatic auxiliary boiler will provide fuel shut off in the case of high （）.
A.water B.voltage C.fuel pressure D.steam pressure
The operating water is supplied under the （）of an oil s...
单项选择题The operating water is supplied under the （）of an oil separator.
A.sliding bowl bottom B.bowl hood C.bowl D.filter units
