横向
1
Medieval land-for-service system
4
Person who travels to discover new lands
5
Government elected by the people
6
Period of ten years
纵向
2
Ancient empire that conquered much of Europe
3
Legislative body in ancient Rome
7
Alloy of copper and tin used in early tools
8
Formal agreement between nations
9
Ancient Mesoamerican civilization
10
Military blockade of a fortified place