The distress signals were sent out, but no one responded.

The ball signals were clearly visible from a distance.

There are many danger signals in this area.

The semaphore signals were used to control the flow of traffic.

The home signals are used to control the movement of trains.

The starting signals were clearly visible from the stands.

The starter signals at the race track were malfunctioning.

There are many danger signals in this area.

The train's cab signals were malfunctioning, causing delays.

The somersault signals were used to indicate the start of the performance.