横向
1
Long and distinct period of history
4
Movement of people to new areas
5
Belonging to a very old period
9
Government elected by the people
11
Person with no fixed home
12
Alloy of copper and tin used in early tools
14
Succession of rulers from same family
15
Ancient Mesoamerican civilization
纵向
2
Government by the people
3
Armed conflict between nations
6
Medieval religious military campaign
7
Handwritten historical document
8
Advanced stage of human society
10
Exchange of goods between peoples
13
Military conflict or fight