platform train indicator

例句：

1. 1.The platform train indicator is a crucial tool for ensuring safe travel on the railway.
   平台火车指示器是确保铁路安全旅行的关键工具。
2. 2.The engineer carefully checked the platform train indicator before starting the engine.
   工程师在启动引擎前仔细检查了平台火车指示器。
3. 3.The platform train indicator is designed to alert passengers when the train is approaching a station.
   平台火车指示器设计用来在火车接近车站时提醒乘客。