Across
1
Low area between mountains
3
Line dividing two countries
4
Region between the two tropic lines
6
Largest river in South America
8
Large slow-moving mass of ice
11
Deep narrow valley with steep sides
Down
2
Large area covered with trees
5
Large natural elevation of earth
7
Where river meets the sea
9
Cold treeless Arctic plain
10
Largest hot desert in the world