横向
1
Land surrounded by water
4
Low area between mountains
5
Region surrounding the North Pole
6
Largest river in South America
9
Seasonal heavy rainfall
12
Wearing away of land by water or wind
纵向
2
Large natural stream of water
3
Flat grassland in tropical regions
7
Piece of land jutting into the sea
8
Mountain that can erupt with lava
10
Region between the two tropic lines
11
Physical features of land