横向
1
Person owned as property
4
Movement of people to new areas
5
Deadly epidemic disease
6
Metal that replaced bronze in tools
7
Period of ten years
10
Period of one hundred years
12
Exchange of goods between peoples
纵向
2
Freedom from outside control
3
Ancient Mesoamerican civilization
8
Fundamental law of a nation
9
Succession of rulers from same family
11
Person who travels to discover new lands