Answer:
Carbon dioxide 
Explanation:
The carbon combines with oxygen to form carbon dioxide (CO2) and is released back into the atmosphere as a waste product when animals breathe and exhale.
 
        
                    
             
        
        
        
Answer:
Glycolysis. 
Explanation:
Glycolysis is a universal process that provides energy in the form of ATP molecules. It requires two molecules of NAD+, which are reduced to NADH during glycolysis. Thus, regeneration of NAD+ is necessary as if NAD+ is absent, glycolysis cannot be able to continue. 
During anaerobic respiration (respiration in the absence of oxygen), fermentation takes place to regenerate NAD+ used in the process of glycolysis.  
 
        
                    
             
        
        
        
I believe it was The Continental Drift Theory , i could be wrong 
        
             
        
        
        
Answer: Heat and pressure compress the mud and carbon over millions of years, forming sedimentary rock such as shale. ... The heated rock recombines into silicate minerals, releasing carbon dioxide. When volcanoes erupt, they vent the gas to the atmosphere and cover the land with fresh silicate rock to begin the cycle again.
Explanation: