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

Example Input: Sentence: 'a few zebras that are next to each other'. Replace the letter 'o' with 'u' in the sentence.
Example Output: a few zebras that are next tu each uther

Example Input: Sentence: 'a baseball player swinging a bat at a ball'. Replace the letter 's' with 'n' in the sentence.
Example Output: a baneball player nwinging a bat at a ball

Example Input: Sentence: 'people stand in a museum and look at a large airplane'. Replace the letter 'a' with 'y' in the sentence.
Example Output:
people stynd in y museum ynd look yt y lyrge yirplyne