Answer:
C
Explanation:
Choices A and B are too short/long to be substitution, and D is the same as the given table.
 
        
             
        
        
        
E. systematic aorta 
D. left ventricle 
C. left atrium
A. pulmonary artery
B. superior venacava (i’m not sure if this one is right)
 
        
             
        
        
        
The answer is oxygen
hope it helps!
        
                    
             
        
        
        
Elephants, who are important grazers, are instrumental in transforming woodlands into grasslands. This has a tremendous impact on other species that depend on the grass for their survival. The significance of the elephant in this example is B. keystone species. 
        
                    
             
        
        
        
<span>Particularly the skeletal muscles at rest
gain most of their energy from the aerobic respiration of fatty acids. Hence
fatty acids provide the majority of the energy for muscle metabolism when a
person is exercising at 25% of VO2max. However, the motor neuron is at rest
when a neuron is not receiving any input there will be a potential difference.
Thus, the potential difference measured when the neuron is inactive and it is
caled the resting membrane potential. </span>