横向
1
Exchange of goods between peoples
3
Ancient Mesoamerican civilization
5
Territory controlled by another country
6
Metal that replaced bronze in tools
8
Advanced stage of human society
9
Object made by humans from the past
纵向
1
Formal agreement between nations
2
Armed conflict between nations
3
Person who buys and sells goods
4
Practice of farming and growing food
7
Government by the people