单项选择题
A.Refrigeration B.Air conditioning C.Ventilation D.Heating
One of the functions of ventilation is to （） the humidi...
单项选择题One of the functions of ventilation is to （） the humidity of spaces containing sources of moisture, or to （） the temperature of spaces not mechanically cooled such as the engine room.
A.increase；reduce B.reduce；increase C.increase；increase D.reduce；reduce
Air conditioning is the process of treating air to cont...
单项选择题Air conditioning is the process of treating air to control （） its temperature, humidity, cleanliness and distribution to meet the comfort requirements of the occupants of the conditioned space.
A.instantaneous B.instantaneously C.simultaneous D.simultaneously
（）, iea steam cooler, may be filled in the boiler syste...
单项选择题（）, iea steam cooler, may be filled in the boiler system to control the superheated steam temperature.
A.An economizer B.An attemperator C.A water dram D.A down-comer tube
