In the ancient world, why did civilizations florist around great river valleys?

Rivers were attractive locations for the first civilizations because they provided a steady supply of drinking water and made the land fertile for growing crops. Moreover, goods and people could be transported easily, and the people in these civilizations could fish and hunt the animals that came to drink water.

Explanation:

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richard nixon led the investigation that resulted in alger hiss being convicted of prejury.

the answer is states.