横向
1
Largest hot desert in the world
4
Dry land with little rainfall
6
Region surrounding the North Pole
7
Physical features of land
8
Deep narrow valley with steep sides
10
Largest river in South America
14
Wearing away of land by water or wind
纵向
2
Largest ocean on Earth
3
Large natural stream of water
5
Flat grassland in tropical regions
9
Where river meets the sea
11
Ocean between Americas and Europe/Africa
12
Low-lying land surrounded by higher ground
13
Long-term weather patterns of an area