Streams erode sediment from their banks. They pick up and transport sediments. As a stream erodes its banks, it creates a V-shaped valley (Figure above). This contrasts with the U-shaped valleys created by glaciers.
        
             
        
        
        
Answer:
use bigger dams,
the underground system clear
make sponge city
 
        
                    
             
        
        
        
Answer: The answer is D) A comparison of physiologic densities and arithmetic densities helps geographers understand
the capacity of land to yield food for the total population
Explanation:
 
        
             
        
        
        
Answer:
Solar flare
Explanation:
A solar flare is an outburst of solar radiation from the surface of the sun outward. This leads to increase in heat intensity and brightness around sun. 
The flare is often accompanied by the ejection of electromagnetic radiations from the surface of the star into the stellar space. It can last from a few minutes to some hours. 
 
        
             
        
        
        
Answer:  The people migrated to other regions of Central Asia.
Explanation: To escape communism.