The one that would not contribute to the structure of Longfellow’s poem would be repetition of phrases. So, C.
Answer:
Understatement.
Explanation:
An understatement is a statement that describes something in a way that makes it sound less important. In this case, if the Army Intelligence calls you up for a meeting, saying that they want to "chat" is an understatement because it's probably much more serious than that.
I think it would be the word of heavy traffic.
What do you mean listening? Elaborate a little?