Across
- 4. natrual boundaries
- 7. trade
- 8. social order
- 9. reflects a society's technology
- 10. sahara desert and desertification
- 11. domestication
Down
- 1. unify
- 2. along river vallys
- 3. affects distribution of population
- 5. ends in 1991 Chinese revolution
- 6. diverse geographical features