Answer:
Atmosphere, plant, animals, fossil fuels.
Explanation:
Carbon Is the essential elements needed for life.
Carbon cycle is the movement of carbon from the atmosphere to the Earth.
Carbon move in the carbon cycle and start from the atmosphere.
In the atmosphere, carbon react with oxygen and it is inform of carbon dioxide. Plants use the carbondioxide along with water,and uses light energy from the sun to produce carbohydrates through a process of photosynthesis.
Animals get carbon from plants after consuming plants.
During respiration, carbon atoms are released to the atmosphere.
Some human activities like burning of fossil fuels releases carbon to the atmosphere.