1. They have not a language as it .. the use a kind of sounds like whistles to comunicate with each others.
2. Dolphins help people because they are allowed to produce very small differences in the frequency or pitch of sound waves they help him making them produce the words.
3. the militares have trained oceanic dolphins to rescue lost naval swimmers.
4. Dolphins have long played a role in human culture. Dolphins are sometimes used as symbols, for instance in heraldry.as helpers of humankind.