History
July 1: SOS danger signals are approved and most commonly used in the world
Many people believe that SOS is an acronym for some rescue questions like
Danger Signal
Browse ScienceInfo articles and explainers related to Danger Signal.
Topic archive
Articles about Danger Signal
2 published items.
Animal world
Teach birds to learn foreign languages to avoid accidents
After only two days of training, the wrenches knew how to flee when they heard the alarm in strange language.