横向
1
One of seven major landmasses
5
Flat grassland in tropical regions
6
Large natural elevation of earth
7
Low area between mountains
9
Wearing away of land by water or wind
11
Cold treeless Arctic plain
12
Largest river in South America
14
Large body of water partly enclosed by land
纵向
2
Height above sea level
3
Land surrounded by water
4
Distance north or south of equator
8
Large natural stream of water
10
Dry land with little rainfall
13
Body of water surrounded by land
15
Region surrounding the North Pole