Measles<span> virus infection is presumed to be sustained through an unbroken chain of</span>human-to-human transmission. So the term I would use is Human Reservoirs  because m<span>any common infectious diseases have human reservoirs. Diseases that are transmitted from person to person without intermediaries . And measles is an example of Human reservoirs. </span> 
        
             
        
        
        
It is d because there is always sun unless you are inside
        
                    
             
        
        
        
Answer:
Sorry, i can't help. 
Explanation:
I can't write your essay for you, that would be plain wrong and morally unacceptable.