Answer: Research with embryonic stem cells may lead to new, more effective treatments for serious human ailments and alleviate the suffering of thousands of people.
Explanation:
 
        
             
        
        
        
Answer:
C if you plug it into the sentance its the only one that makes sense
 
        
                    
             
        
        
        
Let us consider the centripetal force equation,  
centripetal force F = mv² / r  
 f= force
 v= velocity
 m= mass
 r= radius.
 
 in all the factors only velocity has the power of 2. so when you double the velocity then it will become square of that. 
 if v= 2v , F = m4v² / r 
 so velocity is doubled it would produce the greatest change in the centripetal force.
        
             
        
        
        
A. Water being pumped in and out of guard cells.
        
                    
             
        
        
        
Answer:
To prepare a proper seed bed.
Hope this helps!