Carbon dioxide, or CO2.
Plants produce oxygen for us to breathe, and in exchange they take the gas we breathe out: carbon dioxide.
Red, both will be red, the red paper will absorb the white light and putt out red.
1. Distance from the Earth to the Sun
2. Hurt your hand from the reaction force (Newton's 3rd law is every action has an equal and opposite reaction)
3. The Earth to rotate slightly slower (I think)
Hope this helps :)
