Answer:
every cell in you body needs oxygen to help it metabolize it release from food for energy.cells that do the same job combines together to form body tissue such as muscles,skin bone tissue.cells can take in fuel.cells not only make up living things,they are living g things.
 
        
             
        
        
        
Answer:
birch
Explanation:
because they easily germinate hence early succession
 
        
                    
             
        
        
        
Answer:
in the explanation
Explanation:
The independent variable would be us humans polutling the ocean with oil and other plastics destroying the coral reefs. The dependant variable is an abbrasive species of fish becoming overpopulated and killing all the fish that help the coral grow causing the coral to die. (independant variable basically means humans tampering with it causing the problem. dependent is naturally occuring humans cant control whether a fish overpopluates or not thats natural)