1.HVAC system components require routine ______ to ensure proper performance.
1.HVAC（暖通空调）系统的组件需要进行定期的 ______，以确保其正常运行。
2.One ton of refrigeration equals approximately:
2.一冷吨（ton of refrigeration）大约等于：
3.Which instrument measures the relative humidity of air?
3.哪种仪器用于测量空气的相对湿度？
4.One kilowatt-hour equals approximately:
4.一千瓦时（kWh）大约等于：
5.The most suitable flame type for soldering is a:
5.最适合用于软钎焊（soldering）的火焰类型是：
6.Lubricants must have three essential properties. Which of the following is NOT one of them?
6.滑剂必须具备三种基本特性。以下哪项**不属于**这三种特性之一？
7.The weight of one cubic foot of water is about:
7.一立方英尺水的重量大约是：
8.The total volume of the illustrated building is approximately:
8.图示建筑物的总体积大约是：
9.Refrigerants that are recovered must be filtered and ______ before reuse in the same system.
9.回收的制冷剂在同一系统中重新使用之前，必须经过过滤和 ______ 处理。
10.Water being blown from an air handler with supply air is usually caused by:
10.当空气处理机组（air handler）随送风气流吹出水滴时，通常是由什么原因引起的？
