Your answer would be respiration. This would be your answer because, plants take in carbon dioxide, and animals, including humans, breath oxygen. I hope this had helped you out.
CH4+ 2O2---> CO2+ 2H2O I believe would be correct.
Answer:
b
Explanation:
[H3O+] = 10-pH = 10-3.4 ≅ 3.981 x 10^-4 moles/liter