Why were so many cities able to develop between the Tigris and Euphrates rivers?
(a)The cities were protected by mountains to the west.
(b)The forests provided plentiful lumber for construction.
(c)The cities were protected by a vast desert to the east.
(d)The rivers were used for irrigation, which led to a food surplus.
Ancient civilizations had been known to begin developing around rivers, since water was not as abundant. The rivers were commonly used for drinking and irrigation.
