Answer:
The contributions of the Sumerians are creating the first large cities with dense urban populations, building ziggurats or temples, formulating laws, creating a lunar calendar, algebraic expressions and advanced math, use of wheels and engineering skills, clay tokens used as money, and rounded roofs. Their literature contained the stories of the Flood, the Garden of Eden, and the hero Gilgamesh who battled evil, and was a model for future epic heroes.