The traffic signals at the intersection were malfunctioning.

The time-signals are used to indicate the time of day.

The time signals are important for coordinating schedules.

The block signals along the railway track were all red.

The turn signals on my car are not working.

The radar system detected multiple false signals.

I kept getting busy signals when I tried to call my friend.

The police officer was trained to recognize gang signals.

She's giving me mixed signals about her feelings.

The radio signals from outer space are being studied by scientists.