Mystery #2Tier 2burning and breathing
Why do a crackling fire and a running child both need the very same oxygen?
A campfire crackles, and across a field a child sprints as fast as she can. They could not look more different. Yet both would stop dead without the same invisible gas: oxygen. Why does a fire need the very same thing you do?
Your guess
What's your hunch? Why would a fire and your own body both need the same oxygen?
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.