1.Net Energy Gain is a concept used in energy economics that refers to the difference between the energy expended to harvest an energy source and the amount of energy gained from that harvest.
 
        
                    
             
        
        
        
2: D 3: A 4: B 5:A 6:C PLEASE MARK BRAINLIEST!!
        
                    
             
        
        
        
Answer:
Cytoplasm
Explanation:
Cytoplasm is kind of like cell blood. Cell membrane is cell skin, I've legit never heard of a cell skeleton in my life and centrioles are RNA processors. 
 
        
                    
             
        
        
        
They were adapted to an environment and once it is taken away the plants will slowly start to die. I'm not 100% :)
        
                    
             
        
        
        
Answer:
If a solution has a higher concentration of hydronium ions than pure water, it has a pH lower than 7. A solution with a pH lower than 7 is called an acid. As the hydronium ion concentration increases, the pH value decreases. Therefore, the more acidic a solution is, the lower its pH value is.
Explanation: