C.HE UPSET AND WANTS THE KILLERS TO PAY FOR THEIR CRIMES
        
                    
             
        
        
        
When quote marks are used internet search engine searches for exact phrase. It does not separate words. If there were not used quote marks it would show all pages containing words American and folklore.
Key word AND means that internet search engine will show only pages that contain what is before and after that word.
The given search gives results that include entire phrase "American Folklore" and that have word "ghosts inside the page.
Correct answer is: Hits with the entire phrase American Folklore about ghosts.
        
             
        
        
        
Because some music contains bad language.
        
             
        
        
        
Answer:
The class studied poems by these poets; Dickinson, Longfellow, Stevenson, and Poe.
Explanation:
 
        
             
        
        
        
I would say the correct answer is that has an undetermined answer.
If a subject has been thoroughly covered, then there is no need for this researcher to do it all over again. If it's impossible to answer, there is no need to try. If it can be answered easily, then it doesn't really require a research. This leaves us with the last option, because a researcher might want to try and determine the answer.