I think it is because you need them to separate 
        
             
        
        
        
<span>infinitive: "To travel"
To travel is the infinitive form of this verb, which could be conjugated into any other type of verb form, but this is it at its purest. It sets up the sentence without tying it to a subject, and then towards the end relates it back to the type of people the phrase could apply to.</span>
        
                    
             
        
        
        
Answer:
Parenthetical documentation refers to citing sources in parentheses at the end of the evidence.
Explanation:
Parenthetical documentation is used to simplify the way a reader can locate the reference for the information within an essay or any kind of written work, this way the writer doesn't have to add endnotes or a references list or page at the end, this information is located at the end of the citation as mention before between parenthesis.
 
        
             
        
        
        
The impact of Keats's repetition of the word what is that he wants to express the thoughts of the people on the urn. In this way, it will be easier to understand what the people are trying to mean with the urn.