Mystery #3Tier 2breathing out
Why is the air you puff out not the same as the fresh air you breathed in?
Fresh air goes in, used air comes out, over and over, all day long. But the air you puff back out is not quite the same as the air you took in. Somewhere inside you, your body has changed it on the way through. What did it do?
Your guess
What's your hunch? What has your body done to the air by the time you breathe it back out?
There's no single magic word to type, have a go in your own words, then reveal the answer to see how close you got.
Make a guess to unlock the hints and the answer.