In this task, you need to replace a letter in the sentence with another given letter.
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Question: Sentence: 'a man is standing on a snowboard, atop a mountain'. Replace the letter 'd' with 'u' in the sentence.

Answer: a man is stanuing on a snowboaru, atop a mountain


Question: Sentence: 'there is a stepladder situated over a toilet'. Replace the letter 'r' with 'x' in the sentence.

Answer: thexe is a stepladdex situated ovex a toilet


Question: Sentence: 'a zebra is eating hay in a fenced enclosure'. Replace the letter 'e' with 'i' in the sentence.

Answer:
a zibra is iating hay in a fincid inclosuri