单项选择题
A.changing the air filter
B.recharging the system
C.changing compressor lubricant
D.renewing container vacuum
单项选择题 In an air conditioning system, moisture is removed from the air by（）
单项选择题 A lower thermostatic temperature setting will provide a desired degree of comfort in a room where （）
单项选择题 To prevent the unnecessary loading of an air conditioning system while maintaining the designed dry bulb temperature and relative humidity in an air conditioning system, you should （）