The Solar System
|
|
3.2 |
|
|
Space Stations
|
|
3.1 |
|
|
Pluto
|
|
2.8 |
|
|
NASA
|
|
3.1 |
|
|
The Hubble Telescope
|
|
2.9 |
|
|
Astronauts
|
|
3.0 |
|
|
The Moon
|
|
2.5 |
|
|
Space Shuttles
|
|
3.1 |
|
|
Venus
|
|
2.5 |
|
|
Asteroids
|
|
3.2 |
|
|
Coral Reefs
|
|
3.2 |
|
|
Ponds
|
|
2.8 |
|
|
Tundra
|
|
2.9 |
|
|
Wetlands
|
|
2.7 |
|
|
Prairies
|
|
2.4 |
|
|
Glaciers
|
|
2.6 |
|
|
Forests
|
|
2.4 |
|
|
Caves
|
|
2.4 |
|
|
Rain
|
|
1.7 |
|
|
Sunshine
|
|
2.1 |
|
|
Clouds
|
|
2.2 |
|
|
Snow
|
|
1.8 |
|
|
Wind
|
|
2.1 |
|
|
Lightning
|
|
2.2 |
|
|
