单项选择题
A.rub the eyes
B.irritate the eyes
C.wash the eyes with a heavy boric acid solution
D.obtain medical help
单项选择题 （） is the circulation and refreshing of the air in a space without necessarily a change of temperature.
单项选择题 （） is the control of temperature and humidity in a space together with the circulation, filtering and refreshing of the air.
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.