Final answer:
Sumer was next to the Tigris and Euphrates rivers, and the Sumerians built levees, canals, and to control floods. Division of labor is task specialization, and a food surplus enables societal development.
Step-by-step explanation:
Sumer was an ancient civilization located next to the Tigris and Euphrates rivers. To learn to control the flood waters, Sumerians built large-scale levees, canals. Division of labor is the allocation of different tasks to different people or groups in a society, which was necessary due to the complexity of tasks such as those related to large-scale agricultural practices. A surplus of food refers to the production of more food than is immediately needed by the community, allowing people to engage in activities other than agriculture, such as trade, governance, or crafts.
Thus, Sumer was next to the Tigris and Euphrates rivers, and the Sumerians built levees, canals, and to control floods. Division of labor is task specialization, and a food surplus enables societal development.