- An air-raid alarm sounded in the depths of night.
- I raised the alarm as soon as I saw the smoke.
- Expert regard it as a warning signal of an economic smashup.
- By smacking his tail fiat on the top of the water he can also make a loud warning signal when enemies are spotted.
- So they had bypassed the warning signal.
- Acoustic, optical alarm signals and identifying ind.
- Alternative warning arrangements must be made if the noise from the work is likely to mask existing alarm signals.