They allow the heart to pump more blood by decreasing the ESV.
        
             
        
        
        
Answer:
 i think it is the middle one
B
 
        
                    
             
        
        
        
Answer:
hydrosphere
Explanation:
definition: the hydrosphere is the sum of earth's water, in the ocean, the ground, on the surface, and in the air.
 
        
                    
             
        
        
        
Answer:
A concentration gradient occurs when the concentration of particles is higher in one area than another. In passive transport, particles will diffuse down a concentration gradient, from areas of higher concentration to areas of lower concentration, until they are evenly spaced.
well hope this help at least (good night)
 
        
             
        
        
        
Answer:
In short, weather is to describe the day or week (short period). . As for the climate, it is to describe the year or (a long period), for example, the climate of the winter season is cold.