<span>C. the adventures she had experienced during her travels
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Is this from the book Things Fall Apart?
The same thing that happened in the 19th century, "The Great Stink". The name is real and it describes an event from the past which would repeat if they started throwing waste again. The river would become so polluted that disease and contagion would begin to spread. In the 19th century, it was cholera. Now, nobody knows.
One possible reason that the Revolutionary-Era Poets used the iambic meter was to imitate the classical style.