The correct answers are Tigris, Euphrates, Nile, and Indus.
The four major river valleys that were homes to early civilizations were the Tigris, Euphrates, Nile, and Indus.
Major ancient civilizations established close or next to rivers for the purpose of having water, develop agriculture and sanitary reasons. We are referring for instance, to Mesopotamia, that developed major cities between the rivers Euphrates and Tigris, in what now is the region of Iran,. The other example is the Egyptian civilization that benefited so much from the Nile River.
