20.
They told me that my answer was too short so I'm just adding this on, don't mind me.                                    
        
             
        
        
        
Answer:
First leve consumer: 1,000 energy units
Second level consumer: 100 energy units
Third level consumer: 10 energy units
Explanation:
 
        
             
        
        
        
Answer:
A pheochromocytoma is a tumor in the adrenal gland. It causes the gland to make too much of the hormones epinephrine and norepinephrine.
Explanation:
 
        
             
        
        
        
Answer:
The options are :
The spaces get wider because the concrete sections shrink.
The spaces stay the same because the concrete sections does not shrink or expand.
The spaces get narrower because the concrete sections expand.
Some spaces get wider, some spaces get narrower, and some spaces stay the same because each concrete section behaves differently on a hot summer day.
The answer is 
Some spaces get wider, some spaces get narrower, and some spaces stay the same because each concrete section behaves differently on a hot summer day.
Concrete surfaces react with a change in temperature by either shrinking or expanding depending on the temperature difference.
When there is an increase in temperature it expands a bit and shrinks a bit too when the temperature is decreased.
 
        
             
        
        
        
A smaller person would have a lower metabolism rate than a taller person.