横向
1
Roman arena fighter
6
Person who buys and sells goods
7
Ancient Mesoamerican civilization
8
Ancient empire that conquered much of Europe
9
Metal that replaced bronze in tools
10
Sudden overthrow of a government
12
Union formed for mutual benefit
纵向
2
Period of ten years
3
Practice of farming and growing food
4
Payment made to show submission
5
Person who travels to discover new lands
11
Long and distinct period of history