Which was part of Sumerian farming and trading? Select ALL correct answers.

A. Lumber, stone, and gold produced in Sumer could be traded for food.
B. Levees held back the annual floods of the Tigris and Euphrates Rivers.
C. Surplus barley and wheat could be traded for other things.

I think it is B. Levees held back the annual floods of the Tigris and Euphrates Rivers.

Explanation:

lee and grant, both of whom held the highest rank in their respective armies, had known each other slightly during the mexican-american war (1846-48) and began their dialogue by exchanging awkward personal inquiries. characteristically, grant had arrived in his mud-splattered field uniform while lee had turned out in full dress attire, complete with sash and sword.

explanation: