Repeaters

例句：

1. 1.The radio is a device that repeats the same signal over and over again.
   收音机是一种不断重复相同信号的设备。
2. 2. The engineer used a repeater to extend the range of the communication system.
   工程师使用了一个中继器来扩展通信系统的覆盖范围。
3. 3.The repeater was designed to prevent interference from other signals.
   这个中继器被设计用来防止其他信号的干扰。