横向
1
Large natural stream of water
4
Area where water covers the soil
6
Largest hot desert in the world
9
Physical features of land
10
Distance north or south of equator
11
Ridge of rock or coral near the surface
12
Total number of people in an area
13
Flat grassland in tropical regions
纵向
2
Line dividing two countries
3
Mountain that can erupt with lava
5
Half of the Earth
7
Cold treeless Arctic plain
8
Landform where river meets the sea