横向
1
Period of ten years
5
Person owned as property
6
Alloy of copper and tin used in early tools
8
Armed entry into another territory
10
Movement of people to new areas
12
Collection of traditional stories
13
Long and distinct period of history
纵向
2
Medieval land-for-service system
3
Belonging to a very old period
4
Ancient empire that conquered much of Europe
7
Armed conflict between nations
9
Sudden overthrow of a government
11
Exchange of goods between peoples