Explanation:
Bugs, chemicals, and all sorts of other stuff could be in the water if it isn't filtered out, and that could be a major problem for people.
Answer:
Han?
Explanation:
If by civilizations you mean ethnic groups it would be the Han.
Answer:
Tristan da Cunha
Explanation:
Tristan da Cunha is the most remote inhabited island in the world
Islam arrived in the inland of Indian subcontinent in the 7th century when the Arabs conquered Sindh and later arrived in North India in the 12th century via the Ghurids conquest
