The answer is B. 
Animals do cellular respiration which requires the intake of oxygen and the output of carbon dioxide. In order for plants to do photosynthesis, they need carbon dioxide to be able to make oxygen for animals to breathe.
 
        
                    
             
        
        
        
Answer:
The Skeleton
Explanation:
because the softer tissues  and skin usually do not last long enough to become fossilized
 
        
             
        
        
        
Answer:
there are two ATP molecules 
 
        
                    
             
        
        
        
Answer:
Volcanic degassing of volatiles, including water vapour, occurred during the early stages of crustal formation and gave rise to the atmosphere. When the surface of Earth had cooled to below 100 °C (212 °F), the hot water vapour in the atmosphere would have condensed to form the early oceans.
Explanation: