The geography of the fertile Crescent affected the growth of mesopotamian civilizations by?

Tigris and Euphrates

This initially made farming difficult. Two major rivers in the region -- the Tigris and Euphrates -- provided a source of water that enabled wide-scale farming. Irrigation provided Mesopotamian civilization with the ability to stretch the river's waters into farm lands.

d. migration

the graph shows the spread of railways in the 1800s.

based on the graph, the conclusion that can be drawn about germany is answer d)   by 1880, germany had more rail lines than great britain and russia.