This jet stream—the one that forms at the polar front—affects weather in the United States. ... This shift occurs because the entire hemisphere is cooler, so the boundary between the cold polar air and the warm southern air shifts south. As a result, the jet stream shifts toward the south in winter.
 
        
                    
             
        
        
        
Answer:
The correct answer is -  A. Trade
Explanation:
Darius the emperor of the Persian empire was the first Persian emperor to use a coin system for goods, services, and even for tax which makes his economy large and developed his empire, and created a new capaital. Darius used a gold minted coin system for trade for the goods and services and salaries to the army which made his empire popular and a large economy. His economy was a trade economy as coins were used for the different type of goods, foods and services.
 
        
             
        
        
        
Stationary front
warm front=2
occluted front=3
stationary front= 4
cold front=1
        
             
        
        
        
Answer:
need picture brahj, but I got u, when it moves from high concentration to an area of low concentration, a process called diffusion. its process of moving glucose across the cell membrane is called facilitated diffusion.
Explanation: