横向
1
Wearing away of land by water or wind
4
Largest ocean on Earth
7
Large body of water partly enclosed by land
9
Region surrounding the North Pole
纵向
2
Physical features of land
3
Raised area of land, smaller than a mountain
5
Deep narrow valley with steep sides
6
City that is seat of government
8
Piece of land jutting into the sea
10
Flat grassland in tropical regions