Which was part of sumerian farming and trading

Sumerian agriculture and commerce had levees to prevent the annual flooding of the Tigris and Euphrates rivers, and surpluses of barley and wheat that could be exchanged for other commodities.

Explanation:

The Sumerians were the first people to develop cities and build a civilization around 3000 BC around the growing fertile Tigris and Euphrates rivers. These people were noted for having improved the irrigation techniques of the rivers that fed their plantations and the urban areas with population concentration. The Sumerian economy, therefore, was eminently associated with water management and ariculture. Sumerian agriculture and commerce had levees to prevent the annual flooding of the Tigris and Euphrates rivers, and surpluses of barley and wheat that could be exchanged for other commodities.

whats the question? im not quite understanding your question.

disease was the number one killer of native peoples. they had had little exposure to the diseases of europe. this led to some villages being almost completely wiped out and some tribes destroyed.