Instructions: The answer to this question can be given by explaining river valleys and the advantages of living near the river valleys such as fertile plains and availability of water etc.
Solution: In ancient times, the people started settling near the plains of the river valleys. The rivers deposited the fertile alluvial soil making the nearby lands very suitable for agriculture. Hence, growing abundant food became easy.
Moreover, the people got a regular supply of fresh water from the river which they used for irrigating the fields as well as meeting all human needs.The rivers also served as an excellent means of transportation which facilitated easy movement from one place to another. Hence the world's ancient civilizations flourished along the river valleys.