6. What percentage of carbon dioxide is in the Earth atmosphere?
- 0
- 1
- 10
- 21
7. What is the 8th planent away from the sun?
- Mars
- Neptune
- Earth
- Pluto
8. What percentage of oxygen is in the Earth atmosphere?
- 99
- 21
- 65
- 71
9. The Earth has a layered structure but how many layers is there?
- 2
- 4
- 0
- 5
10. What is the 4th planet away from the sun?
- Saturn
- Mercury
- Mars
- Uranus
