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

Example Input: Sentence: 'bags of seeds with a pair of black scissors sitting on them'. Replace the letter 'b' with 'y' in the sentence.
Example Output: yags of seeds with a pair of ylack scissors sitting on them

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 drink in a glass with an ice cube'. Replace the letter 'i' with 'y' in the sentence.
Example Output:
a drynk yn a glass wyth an yce cube