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

Sentence: 'a red hydrant is sitting on the sidewalk in the city'. Replace the letter 'n' with 'r' in the sentence.
a red hydrart is sittirg or the sidewalk ir the city

Sentence: 'a geoup of people on bicycles coming down a street'. Replace the letter 'i' with 'x' in the sentence.
a geoup of people on bxcycles comxng down a street

Sentence: 'a small dog is standing on a motorcycle'. Replace the letter 's' with 'm' in the sentence.

a mmall dog im mtanding on a motorcycle