1.After installation is completed, operation and maintenance guidelines are typically mounted on the ______.
1.安装完成后，操作与维护指南通常张贴在 ______ 上。
2.Circular bends must be at least ___inch wide and no thinner than the duct’s metal gauge.
2.圆形弯头（弯管）的宽度必须至少为 ___ 英寸，且厚度不得小于风管本身的金属板厚度。
3.Electric unit heaters must comply with local regulations and commonly follow the:
3.电加热机组必须符合当地法规，且通常遵循：
4.The maximum a recovery cylinder should be filled is:
4.回收钢瓶的充装上限为：
5.Special heat-transfer ______ tapes are used to distribute heat from tracing around the pipe circumference.
5.特殊的传热 ______ 胶带用于将伴热带产生的热量沿管道圆周方向均匀散布。
6.An economizer combines which two air streams?
6.节能器（Economizer）结合了哪两种气流？
7.Unit heaters are typically available in three types. Which one is NOT included?
7.单元式加热器通常分为三种类型。以下哪一项不包含在内？
8.Flat floor furnaces must be installed at least ___ inches away from walls.
8.平板式地板炉（Flat floor furnaces）的安装位置必须距离墙壁至少 ___ 英寸。
9.Electric snow-melting systems come in three main types. Which of the following is NOT one of them?
9.电动融雪系统主要分为三种类型。以下哪一项不属于其中之一？
10.Metal ducts must not be placed in or within___inches of soil.
10.金属风管不得埋入土壤中，也不得置于距离土壤 ___ 英寸的范围内。
