In this task, you need to replace a letter in the sentence with another given letter.

Q: Sentence: 'a blue and white train is coming down some tracks'. Replace the letter 'b' with 'u' in the sentence.

A: a ulue and white train is coming down some tracks
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Q: Sentence: 'a person on a snow board flying through the air'. Replace the letter 'f' with 'n' in the sentence.

A: a person on a snow board nlying through the air
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Q: Sentence: 'a cat is wearing a pink wool hat'. Replace the letter 'c' with 'm' in the sentence.

A:
a mat is wearing a pink wool hat
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