横向
1
Line dividing two countries
3
Largest river in South America
5
Steep rock face at edge of land
8
Large natural stream of water
纵向
2
Wearing away of land by water or wind
4
Distance east or west of prime meridian
6
Largest hot desert in the world
7
Cold treeless Arctic plain
9
Piece of land jutting into the sea
10
Distance north or south of equator