Answer:
okay... we brEathe out carbon dixide so IM GEUSSING ITS the plants take in the carbon D.. so PLANTS TAKE IN OUR CARBON DIOXIDE :) UMMM REMEBER WE BREATHE OUT CARBON D... AND PLANTS BRATHE IN WHAT WE BREATHE OUT .. AND WE BRAETHE THEIR PRODUCT air:)GOOD LUCK IF IT HELPS..