横向
1
Area where water covers the soil
5
Largest ocean on Earth
6
Deep narrow valley with steep sides
7
Landform where river meets the sea
9
Goods sold to another country
10
Piece of land jutting into the sea
纵向
2
Largest river in South America
3
Wearing away of land by water or wind
4
Total number of people in an area
8
Flat grassland in tropical regions