The repeated phrase here is "Let freedom ring" and this shows the idea that America needs to become free.
This refers to the constant use of a word or phrase to make an emphasis on something.
Hence, we can see that from the given text, there is the narration by MLK about America and he uses repetition of phrases to do this and this shows the importance idea of freedom.
Read more about repetition here:
https://brainly.com/question/9134427
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