Answer:
the first one is increase and the second one is cell differentation
Explanation:
 
        
             
        
        
        
Physical activity causes an increase in your heart rate. Your body have to change the way it behaves so you don’t get ill or sick or pass out during physical exertion
        
             
        
        
        
Here's a graph showing the stages. 
Look closely at the second stage-- the death rate is low but the birth rate is high. 
It's <span>
D. The death rate begins to fall, but birth rates remain high for a time.</span>
 
        
        
        
The lack of detail and scaling makes the Appalachian trail map useless. An evidence coming from the story is it has a scale of 1:100,000 which compresses the places, the routes, trails of the real world into a mere centimeter in the map.