Answer:
 A they break down glucose moleculws
 
        
                    
             
        
        
        
Answer;
Glucose
The nutrient that can be used to produce energy in the absence of oxygen is glucose.
Explanation;
Production of energy without using glucose is called anaerobic respiration. During this type of respiration less energy is released than the case of aerobic respiration. This is because the breakdown of glucose is incomplete. Anaerobic respiration produces an oxygen debt, which is the amount of oxygen needed to break lactic acid to carbon dioxide and water.
        
             
        
        
        
A cell of the nervous system is <u>neuron.</u><u>.</u><u>.</u>
 
        
                    
             
        
        
        
Answer:
protein
Explanation:
see attached for human skill 
 
        
             
        
        
        
The role of liver is It produces bile