entrance relay

例句：

1. 1.The entrance relay is responsible for controlling the flow of traffic at the entrance.
   入口继电器负责控制入口处的交通流量。
2. 2. The entry relay was designed to improve the efficiency of the system.
   入口继电器的设计目的是为了提高系统的工作效率。
3. 3. The entry relay was a critical component in the security system.
   入口继电器是安全系统中的一个关键组件。