1.Which device is specifically intended to reduce AC voltage from a higher level (e.g., 230V) to a lower level (e.g., 12V)?
1.哪种设备专门用于将交流电压从较高电平（例如 230V）降低到较低电平（例如 12V）？
2.A security camera must cover a target 25 feet away, with an approximate field of view 15 feet high and 20 feet wide. Which lens focal length meets this requirement according to the lens chart?
2.一台安全摄像机需要覆盖25英尺外的目标，其视野范围约为15英尺高、20英尺宽。根据镜头图表，哪种焦距的镜头符合此要求？
3.When cross-connecting analog telephone lines on a 66 or 110 block, which wire type and gauge is standard for punch-down terminations?
3.在66或110接线块上交叉连接模拟电话线时，哪种类型的导线和线规是用于压接端接的标准？
4.Which tool, often fired into concrete/steel, requires secure storage due to its mechanism?
4.哪种工具通常用于混凝土/钢材，由于其工作原理需要安全存放？
5.Which portable tool has a ＂lock-on＂ button for continuous operation?
5.哪种便携式工具带有“锁定”按钮，可实现连续操作？
6.Which type of drill is specifically built to drill into concrete, brick, or masonry using a rotating hammer action to break up the material?
6.哪种类型的电钻专门用于钻混凝土、砖块或砌体，并使用旋转锤击作用来破碎材料？
7.What is the most accurate way to determine the length of cable remaining on a spool?
7.确定线轴上剩余电缆长度的最准确方法是什么？
8.A low-voltage installer needs to wire 25 offices with Cat6 voice and data drops. If the average run is 150 feet per office, how many 1,000-foot cable boxes are required?
8.一位低压安装人员需要为 25 个办公室布设 Cat6 语音和数据线。如果每个办公室的平均布线长度为 150 英尺，则需要多少个 1000 英尺的电缆箱？
9.While developing a cost proposal for a telephone system installation, which overhead expense is most often overlooked but should be accounted for in the estimate?
9.在制定电话系统安装成本方案时，哪项间接费用最容易被忽略，但应该包含在估算中？
