According to the passage, which of the following statement is right for the ancient Sumerians?
A.
The ancient Sumerians built the present-day lraq.
B.
The ancient Sumerians started agriculture when they produced rice.
C.
The ancient Sumerians began fermenting beer from barley at least 6,000 years ago.
D.
The ancient Sumerians began fermenting beer from barley at least 600 years ago.