Answer:
 "it was once part of the organisms from which the fossil fuels formed"
 
        
             
        
        
        
Biomechanical mechanisms, habitat for plants and animals, participates in cycling of all materials used by living things.
        
             
        
        
        
Adenine, thymine, guanine, and cytosine
        
             
        
        
        
<span>well i take this test before and the correct answer is :A They produce food by photosynthesis</span>