The Sumerians were able to build of dams and, to provide their with regular supply of.

The Sumerians were able to build networks of canals, dams, and reservoirs to provide their crops with a regular supply of water.

Explanation:

The Sumer becomes the first civilizations in world history. The Sumerians were first to conquer neighbours and build an empire. The kingdoms of Sumer organized into city-states. It was not easy to live in the Fertile Crescent called Mesopotamia. There was a little rain as they were farmers and needed water for crops. The rivers carried water in flood season, but the soil remains tough and dry. To overcome the situation the Sumerians came with the idea of canals, dams, and reservoirs to store water for farming.

montesquieu took the view that the roman republic had powers separated so that no one could usurp complete power. in the british constitutional system, montesquieu discerned a separation of powers among the monarch, parliament, and the courts of law.

the answers are a b and d