Hunger is your body telling you that your body is hungry, appetite is you conscious telling you aren't hungry, although you probably are
        
                    
             
        
        
        
Answer:
Incidence
Explanation:
Isaac will need to assess the incidence rate of HIV-infected adolescents for his research. This must be done because Isaac's research wants to gauge the speed with which this virus is spreading among teens. For this, Isaac must make a comparison between the existing number of patients who fit this case, with patients who fit the recent cases of incidence of the disease. That is, when conducting his research, he will want to examine the number of new cases, the incidence of the disease.
 
        
             
        
        
        
Providing equipment that encourages children to take charge of their own active play.
        
             
        
        
        
Answer:
Public Service Announcement (abbreviated PSA)
 
        
             
        
        
        
Answer:
Right atrium, right ventricle, left atrium, and left ventricle.