Answer:
The four major river valleys that were homes to early civilizationes are Yellow, Nile, Indus and Tigris and Eufrates.
Step-by-step explanation:
Early agricultural civilizations settled on river valleys because of the advantages it had for growing crops. The first agricultural civilizations settled on the Nile, the Egiptian civilization; and between the Tigris and the Eufrates, where Mesopotamia was founded.
Later on, the Indian civilization settled along the Indus river and the Chinese along the Yellow river.