1.Which gas must never be used to pressurize a refrigeration system?
1.哪种气体绝对不能用于制冷系统的加压？
2.The symbol shown in the figure represents which construction blueprint item?
2.图中所示的符号代表施工图纸上的哪个部件？
3.The symbol shown in the figure corresponds to which device?
3.图中所示的符号对应于哪个设备？
4.What is the proper way to check refrigerant charge in an existing HVAC system in California?
4.在加利福尼亚州，检查现有暖通空调系统中制冷剂充注量的正确方法是什么？
5.Which condition is generally not a concern when installing HVAC equipment at low elevations near coastal areas?
5.在沿海地区低海拔地区安装暖通空调设备时，以下哪种情况通常无需担心？
6.With which motor type should loose clothing be avoided for safety reasons?
6.出于安全考虑，使用哪种类型的电机时应避免穿着宽松的衣服？
7.When duct size is reduced, causing velocity pressure to rise, what additional effect occurs?
7.当风管尺寸减小，导致风速压力升高时，还会产生什么其他影响？
8.On a thermostat, what does the terminal letter “O” represent?
8.在温控器上，端子字母“O”代表什么？
9.Hot air furnaces are designed as self-contained and self-______ units.
9.热风炉设计为独立式和自______单元。
10.Which of the following is not a standard manufacturer equipment classification?
10.以下哪项不是制造商的标准设备分类？
