横向
1
Movement of people to new areas
6
Armed entry into another territory
7
Formal agreement between nations
8
Metal that replaced bronze in tools
9
Union formed for mutual benefit
纵向
2
Government elected by the people
3
Long and distinct period of history
4
Sudden overthrow of a government
5
Male monarch ruler
10
Government ruled by a king or queen
11
Territory controlled by another country
12
Ancient Mesoamerican civilization
13
Freedom from outside control
14
Medieval land-for-service system