横向
1
Large natural stream of water
3
Large area covered with trees
4
Wearing away of land by water or wind
7
Mountain that can erupt with lava
8
Flat grassland in tropical regions
纵向
1
Ridge of rock or coral near the surface
2
Line dividing two countries
5
Vast body of salt water
6
Seasonal heavy rainfall
9
Imaginary line around the middle of Earth