Across
- 2. artificial human-made system of watering crops
- 5. point where two or more lines interconnect
- 8. what humans lived as for most of their time on Earth
- 9. when cities start to spread out into the surrounding rural areas
Down
- 1. lifestyle characterized by moving place to place
- 3. where the world's earliest cities developed near
- 4. things like roads, buildings, electrical grids
- 6. where cities started to appear in the U.S. after the Transcontinental Railroad
- 7. places where people started to work during industrialization
- 9. the introduction of agriculture allowed for a food ___