单项选择题
When starting air-conditioner in the winter, we should open（）in sequence. Ⅰ.alve of warming Ⅱ.alve of humidifier Ⅲ.an
A.Ⅲ-Ⅱ-Ⅰ B.Ⅲ-Ⅰ-Ⅱ C.Ⅰ-Ⅲ-Ⅱ D.Ⅱ-Ⅲ-Ⅰ
单项选择题 The air-conditioner is running in the winter and to be stopped, we should（）
单项选择题 The humidifier’s valve of air-condition should be （）, when the temperature is lower than 0℃.
单项选择题 The humidifier’s valve of air-conditioner should be （）, when the temperature is 5~8°C in the winter.
