单项选择题
A.fresh water B.fresh air C.salt water D.artificial respiration
If liquid refrigerant accidentally comes in contact wit...
单项选择题If liquid refrigerant accidentally comes in contact with the eyes, （） immediately.
A.rub the eyes B.irritate the eyes C.wash the eyes with a heavy boric acid solution D.obtain medical help
（） is the circulation and refreshing of the air in a sp...
单项选择题（） is the circulation and refreshing of the air in a space without necessarily a change of temperature.
A.Refrigeration B.Air conditioning C.Ventilation D.Heating
（） is the control of temperature and humidity in a spac...
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.
