横向
1
Seasonal heavy rainfall
4
Ridge of rock or coral near the surface
7
Large area covered with trees
8
Deep narrow valley with steep sides
10
Largest river in South America
11
Line dividing two countries
12
Visual representation of an area
纵向
2
Physical features of land
3
Wearing away of land by water or wind
5
Ocean between Americas and Europe/Africa
6
Goods brought in from another country
9
Area where water covers the soil