Answer:
The first dwellers of the Indus River Valley were an agicultural civilization which later developed fortified cities and a big commercial network with Egypt and Mesopotamia. This civilization, alike with the other 2 civilizations, used the floods of the river to water the crops.
Around 15000 BCE, the river began to dry supposedly to deforestation and the drought caused the civilization of the Indus River to collapse. Also, some specilists think that the immigration of other people and climate change may have contributed to the decay of the first big civilization.
Afterwards, the valley of the Indus River was colonized by the Ghandara Grave Culture which latter had continuity with the Indo-Aryan people.
Explanation:
