This is because carbon dioxide comes from many things pure if you added anything to it ( like oxygen, or methane ) then It would not be even close to being carbon dioxide anymore...
I hope that this helps you. :)
The answer is a!!!!!!!!!!
Answer:
Tell him u like him and be respect his idea of what he say it’s a 50/50 chance he likes u. I really believe u can do it.
Explanation:
The answer is Strontium Nitride