横向
1
Wearing away of land by water or wind
5
Deep narrow valley with steep sides
6
Largest river in South America
7
Ocean between Americas and Europe/Africa
8
Imaginary line around the middle of Earth
纵向
2
Total number of people in an area
3
Mountain that can erupt with lava
4
Line dividing two countries
9
One of seven major landmasses
10
Large body of water partly enclosed by land