横向
1
Land surrounded by water on three sides
4
Line dividing two countries
6
Imaginary line around the middle of Earth
7
Wearing away of land by water or wind
10
Low area between mountains
11
Large area covered with trees
12
Largest river in South America
纵向
1
Total number of people in an area
2
Distance east or west of prime meridian
3
Flat grassland in tropical regions
5
Piece of land jutting into the sea
6
Where river meets the sea
8
Cold treeless Arctic plain
9
Narrow sea inlet between cliffs