横向
1
Large slow-moving mass of ice
3
Deep narrow valley with steep sides
4
Cold treeless Arctic plain
6
Land surrounded by water
7
Largest ocean on Earth
9
Mountain that can erupt with lava
10
Largest hot desert in the world
纵向
2
Flat grassland in tropical regions
5
Ocean between Americas and Europe/Africa
8
Largest river in South America
11
Total number of people in an area