Could someone explain the addition of carbon in the carbon cycle

When plants and animals die, their bodies, wood and leaves decays bringing the carbon into the ground. Some is buried and will become fossil fuels in millions and millions of years. Carbon moves from living things to the atmosphere. Each time you exhale, you are releasing carbon dioxide gas (CO2) into the atmosphere.

the answer is: metamorphic rocks often show the presence of fossils, also a

hope i

-lavira: )