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

Q: Sentence: 'a train traveling through a dark tunnel next to green brush.'. Replace the letter 'r' with 'e' in the sentence.

A: a teain teaveling theough a daek tunnel next to geeen beush.
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Q: Sentence: 'a mouse and keyboard sitting on a wooden desk'. Replace the letter 'a' with 'n' in the sentence.

A: n mouse nnd keybonrd sitting on n wooden desk
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Q: Sentence: 'a large plane on a landing strip surrounded by workers'. Replace the letter 'i' with 'u' in the sentence.

A:
a large plane on a landung strup surrounded by workers
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