横向
1
Person owned as property
4
Fundamental law of a nation
5
Medieval land-for-service system
8
Formal agreement between nations
纵向
2
Alloy of copper and tin used in early tools
3
Government ruled by a king or queen
4
Practice of establishing foreign colonies
6
Military blockade of a fortified place
7
Advanced stage of human society
9
Practice of farming and growing food