It's too dry to grow crops. People in these regions have become nomadic herders and they must move their herds to find water and grass. The people also might have to adjust to find ways to get water such as developing an irrigation system.
        
                    
             
        
        
        
I believe the correct answer is A
 
        
             
        
        
        
Answer:
an period of high-stakes tension  between russia and us
Explanation:
*** nuclear arms race--> they both attempted to gather as many nuclear weapons as possible to act like a threat to the other
the cw was a period of geopolitical tension between the su and the us  and their respective allies, the 'Eastern Bloc and the Western Bloc', after WW II. 
--> the period is generally considered to span the 1947 Truman Doctrine to the 1991 dissolution of the su. 
 
        
                    
             
        
        
        
The answer is <span>Muhammad</span>