横向
1
Deep narrow valley with steep sides
4
Low-lying land surrounded by higher ground
5
Seasonal heavy rainfall
6
Largest ocean on Earth
8
Ridge of rock or coral near the surface
9
Large natural stream of water
纵向
2
Visual representation of an area
3
Tool for finding directions
6
Total number of people in an area
7
Wearing away of land by water or wind
10
Line dividing two countries