救援队通过船只的应答器定位了遇险船只。

The rescue team located the distressed vessel using its ___transponder.

如果你的车辆没有安装应答器，就只能在人工收费通道排队。

If your car doesn't have a ___transponder installed, you'll have to queue at the manual toll lane.

飞机上的应答器帮助空中交通管制跟踪其位置。

The airplane's ___transponder helps air traffic control track its position.