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

Example Input: Sentence: 'a basket holds flowers, twigs, and various fruits'. Replace the letter 'a' with 'g' in the sentence.
Example Output: g bgsket holds flowers, twigs, gnd vgrious fruits

Example Input: Sentence: 'a crooked street sign on a damaged sidewalk'. Replace the letter 'm' with 'u' in the sentence.
Example Output: a crooked street sign on a dauaged sidewalk

Example Input: Sentence: 'people on a beach on a cloudy stormy day'. Replace the letter 'c' with 'q' in the sentence.
Example Output:
people on a beaqh on a qloudy stormy day