Final answer:
In a poem, the term "Duo" mentioned in line 13 likely refers to two related elements, themes, or characters that are being compared or contrasted within the text.
Step-by-step explanation:
The "Duo" referred to in line 13 of a poem could be alluding to a pair of items, individuals, or concepts that the poem addresses or represents. In the context of the provided excerpts, which discuss cultural reference points, the "Duo" could signify two elements being compared or contrasted within the poem, such as the juxtaposition of war in foreign lands with the conflict on the streets in the United States, or the comparison between the societal impact of the war on drugs and the unfair treatment of specific demographics. The term "Duo" highlights the connectivity and relationship between two distinctive entities, which could be themes, characters, events, or other literary elements that the speaker in the poem wants to draw attention to.