Across
1
Large natural stream of water
2
Total number of people in an area
3
Flat grassland in tropical regions
4
Vast body of salt water
7
Distance east or west of prime meridian
8
Flat elevated area of land
Down
2
Land surrounded by water on three sides
5
Imaginary line around the middle of Earth
6
Region between the two tropic lines
9
Wearing away of land by water or wind
10
Largest ocean on Earth