Mesopotamia, China, Egypt, and India were all river valley civilizations, meaning they arose in the valleys of major rivers. Mesopotamia arose on the Tigris and Euphrates rivers; china on the Yellow river; Egypt on the Nile river; and India on the Indus river. Irrigation systems were built to control water for farming. All four civilizations were governed by kings who derived their authority form the gods(either they claimed to be a god themselves or they claimed to by appointed by the gods). All were polytheistic and their gods were usually tied to nature. All had hieroglyphic writing systems. The Indus valley civilizations writing system has yet to be deciphered so researchers know little about the civilization. All were a patriarchal society were the eldest male in the extended family had the greatest authority. They all also developed metallurgical skills and made important cultural achievements. In Mesopotamia, the wheel, the sundial, number system based on 60, construction, irrigation systems, mathematics and astronomy, and a writing system; in China, paper, wheelbarrow, watermills, construction, writing system, and irrigation systems. In India, construction, writing system, and irrigation system; in Egypt, writing system, irrigation system, calendar based on 365 days, construction, and a form of papyrus.…