横向
1
Total number of people in an area
5
Area where water covers the soil
6
Region surrounding the North Pole
8
Cold treeless Arctic plain
11
Distance north or south of equator
12
Largest river in South America
13
Deep narrow valley with steep sides
纵向
2
Steep rock face at edge of land
3
Large natural stream of water
4
Physical features of land
7
Tool for finding directions
9
Ocean between Americas and Europe/Africa
10
Region near the equator