Answer:
b. There has been little to no recent growth in renewable energy use due to a lack of environmental concerns with the use of fossil fuels. 
Explanation:
Fossil fuels have had tremendous negative impacts on the environment and humans as well. For that reason, the use of renewable sources of energy, such as hydropower and biomass, have become increasingly popular over the last few decades.
 
        
                    
             
        
        
        
Answer:
 an independent variable is a variable that we choose to change to see that happens. ( eg. the temperature when testing evaporation). 
a dependent variable is the variable that we measure. ( so maybe how much water evaporates)
 
        
                    
             
        
        
        
Examples: plant & animal cells, sperm & ovum, bacteria & virus