Carbon monoxide is a gas produced by furnaces and other devices that burn fuel, and any fuel that is incompletely burned produces carbon monoxide, a colorless, odorless gas. Given these facts, what happens when a fuel burns incompletely among the following options:
- Carbon monoxide disappears
 - direct damage to the lungs
 - deadly and devastating
 - Carbon monoxide is created
 - retaining heat
 - Oxygen increases
 - permineralization
 - It's recycled


 

    Carbon monoxide is created     