The correct answer is metaphor.
A metaphor is a rhetorical figure of speech where two or more things are symbolically compared, without using the words such as like or as (because that would be a simile). This whole poem is symbolical/metaphorical - it talks about the passage of time and how everything is transient and fleeting.
Answer:
nasty : unpleasant because they are both synonyms for each other.
Explanation:
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