横向
1
Large area covered with trees
4
Region between the two tropic lines
5
Largest river in South America
7
Deep narrow valley with steep sides
9
Physical features of land
10
Cold treeless Arctic plain
纵向
2
Large natural stream of water
3
Flat elevated area of land
6
Ridge of rock or coral near the surface
8
Wearing away of land by water or wind
11
Low-lying land surrounded by higher ground
12
Total number of people in an area
13
Goods brought in from another country