横向
1
Body of water surrounded by land
4
Total number of people in an area
5
Cold treeless Arctic plain
6
Large natural stream of water
8
Region near the equator
纵向
2
Steep rock face at edge of land
3
Wearing away of land by water or wind
7
Largest river in South America
9
One of seven major landmasses
10
Area where water covers the soil