CIVILIZATION
Another Answer
American English uses the 'Z'; British Englishes uses the 'S'. This is common in many words.
Obviously not or we would not be referring to them as "early" civilisations.
Sumer and Egypt were contemporary civilizations with Harappa.
earlier civilisations, of course.
Well, stone age cultures were the earliest, but if you want actual civilisations? Probably Sumer, Assyria and Egypt
Iron age civilizations emerged after bronze age civilizations and were characterized by the widespread use of iron tools and weapons instead of bronze. Iron age societies typically had larger and more complex political structures and social systems compared to bronze age societies. Iron age civilizations also experienced advancements in agriculture, transportation, and warfare.
Nomadic peoples migrated in and there was a period of unsettlement until the nomads settled in and established civilisations of their own.
they sat on it.
Presumably they could use any suitable caves (if available) as shelters and store-rooms, but water is important to ALL civilisations!
The classical civilisations were intent on protecting themselves from depredations by the peoples, and often traded with them, and sought to expand their empires by taking them over.
China,Japan,Europe this is at particular time by the way
The river valleys favored the rise of early civilizations because the rivers provided a continuous supply of water for farming and human consumption.
Some ancient civilizations such as the Mayans believed in human sacrifice in order for the natural cycle of seasons to continue. The Mayans would sacrifice prisoners from the top of their stone temples.