横向
1
Exchange of goods between peoples
4
Union formed for mutual benefit
5
Formal agreement between nations
9
Alloy of copper and tin used in early tools
10
Sudden overthrow of a government
13
Ancient Mesoamerican civilization
纵向
2
Metal that replaced bronze in tools
3
Person who buys and sells goods
6
Military conflict or fight
7
Period of one hundred years
8
Medieval land-for-service system
11
Armored warrior of medieval times
12
Government ruled by a king or queen