1. Deserts and mountains surround the Fertile Crescent to the north but because grass grew on these mountains it attracted wandering tribes who often attacked those living in the River Valley.

2. Both rivers overflow in an unpredictable manner.

a. The time of year could not be predicted.

b. The magnitude of turbulence of the flooding could not be predicted.

4. The area is called a "crossroad" because everyone who traveled or traded between Europe, Africa, and Asia traveled through this region, sometimes taking what they wanted.