ANSWER:
A civilization exists for several hundred years, developing its own language. Such a civilization probably has been suffering from a lack of contact with the outside world and also isolated by mountains or some other physical barriers.
Step-by-step explanation:
- The mass of people with the isolated civilization are out of the touch from the outside world and do not have the physical contact with any outsiders except those isolated mass.
- These civilizations do not depend upon any help or trade other than themselves.