jphyolinn677 jphyolinn677 26-08-2022 History contestada Which statements were a factor in the decline of Sumer? Select all correct answers. The cultivated soil had poor drainage. The cultivated soil had poor drainage. Nomads invaded Sumerian city-states. Nomads invaded Sumerian city-states. A drought caused poor crop production. A drought caused poor crop production. Salinization of the soil occurred.