Across
1
Line dividing two countries
3
Mountain that can erupt with lava
5
Height above sea level
6
Flat grassland in tropical regions
8
Body of water surrounded by land
10
Large natural elevation of earth
11
Goods brought in from another country
Down
2
Cold treeless Arctic plain
4
Largest river in South America
7
Land surrounded by water
9
Large area covered with trees
12
Raised area of land, smaller than a mountain