SOS is an international distress signal. In daily life, SOS is usually understood as "saving our ship" and "saving our soul". However, it didn't mean anything when the specification was made, just because Morse code is all-dot and all-horizontal, which is convenient for recording.

With the development of modern radio communication technology, ships and spacecraft use Morse code for communication less and less. So SOS has gradually stopped except amateur radio and changed to GMDSS (International Maritime Satellite Electronic Communication Equipment).

Example:

The ferry didn't even have time to send a distress signal. ?

The ferry didn't even have time to send out an emergency signal.

We received an emergency distress signal for food parcels in this area. ?

We received an urgent message for help from that area. They are in urgent need of food packages.

3. If you see some threats, or if the child feels dangerous under any circumstances, he can press the SOS button. ?

If you see a threat, or the child feels dangerous under any circumstances, he can press the emergency help button.

His successor in SOS is Colonel Henry B. Sailor. ?

His successor was Colonel Henry B. Sailor.

The SOS movement is part of it. ?

This operation is only part of the job.