1.All hot-water systems require some form of ______ to overcome resistance caused by water flow.
1.所有的热水系统都需要某种形式的 ______ 来克服水流产生的阻力。
2.A connector used to join a flared copper tube to a pipe is called a:
2.用于连接扩口铜管与管道的接头被称为：
3.Suspended unit heaters must be supported by structures designed to handle both weight and ______ loads.
3.悬挂式单元加热器必须由能够承受其自重及 ______ 载荷的结构进行支撑。
4.The pressure from a moving fluid against a perpendicular surface is termed:
4.运动流体作用于垂直表面所产生的压力被称为：
5.Which valve type is most commonly used to regulate fuel gas flow to burners?
5.种类型的阀门最常用于调节输送至燃烧器的燃料气体流量？
6.Air is considered stagnant when its movement drops below:
6.当空气的移动速度降至 ______ 以下时，即被视为处于停滞状态。
7.Natural gas piping systems are usually constructed from ______.
7.天然气管道系统通常由 ______ 制成。
8.Refrigerant piping for Freon systems is typically made of ______.
8.氟利昂（Freon）制冷系统的制冷剂管道通常由 ______ 制成。
9.The difference between static pressure and total pressure is known as:
9.静压与全压（总压）之差被称为：
10.A steam distribution system must remain free of ______ and condensate.
10.蒸汽分配系统必须保持无 ______ 和冷凝水。
