横向
1
Landform where river meets the sea
4
Wearing away of land by water or wind
6
Line dividing two countries
7
One of seven major landmasses
9
Large body of water partly enclosed by land
10
Largest ocean on Earth
11
Goods sold to another country
12
Deep narrow valley with steep sides
13
Land surrounded by water
纵向
2
Half of the Earth
3
Cold treeless Arctic plain
5
Flat grassland in tropical regions
8
Distance east or west of prime meridian