横向
1
Low-lying land surrounded by higher ground
4
Large natural stream of water
6
Height above sea level
7
Goods sold to another country
9
Raised area of land, smaller than a mountain
10
Land surrounded by water
纵向
2
Wearing away of land by water or wind
3
Flat grassland in tropical regions
5
Large slow-moving mass of ice
8
Region near the equator
11
Line dividing two countries
12
One of seven major landmasses
13
Physical features of land