coupler for frequency meter

例句：

1. 1. The circuit board has a coupler for connecting to the motherboard.
   电路板有一个耦合器用于连接到主板。
2. 2.The new car comes with a coupler for connecting the radio to the dashboard.
   新车配有一个耦合器用于将收音机连接到仪表盘上。
3. 3. The engineer used a coupler to connect the wires together without damaging them.
   工程师使用了一个耦合器来连接电线，而不损坏它们。