2. Sumerians used water from the Tigris and Euphrates rivers to water crops.
3. Sumerians used irrigation to water their crops, which increased harvest. People began to live together therefor developing cities.
4. Plentiful food allowed some Sumerians to specialize in work other than farming such as artisan.
5. The terrain of Mesopotamia had very fertile soil from the rain that flowed from the mountains. Southern Mesopotamia is made up of marshy areas. Southern Mesopotamia also had flat and barren plains.
Answer:Obsidian was volcanic glass in a ring of volcanoes along the Pacific coast of the Maya area. Mayan technicians made techniques for cutting sharp blades. As said, Mayans used specialized jade tools that helped their technological achievements. Maya is thought to be the first civil engineers of the Americas.
