Answer:
Irrigation
Explanation:
One of the innovations that most directly led to the development of the first city-states was that of irrigation. Irrigation allowed farmers to control the water supply used for growing crops. This was a very important development, as it allowed agriculture to become more regular and predictable. As agriculture became better established, a surplus of food allowed population to grow. A larger population required more sophisticated systems of organization, which led to the first city-states.
