横向
1
Line dividing two countries
4
Total number of people in an area
5
Imaginary line around the middle of Earth
6
Goods brought in from another country
8
Vast body of salt water
纵向
2
One of seven major landmasses
3
Region surrounding the North Pole
4
Largest ocean on Earth
7
Wearing away of land by water or wind
9
Area where water covers the soil