横向
1
Region surrounding the North Pole
3
Flat grassland in tropical regions
7
Ocean between Americas and Europe/Africa
8
Low area between mountains
9
Ridge of rock or coral near the surface
10
Region between the two tropic lines
纵向
2
Deep narrow valley with steep sides
4
Wearing away of land by water or wind
5
Long-term weather patterns of an area
6
Flat elevated area of land
11
Large slow-moving mass of ice
12
Raised area of land, smaller than a mountain
13
Land surrounded by water on three sides