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

Example Input: Sentence: 'mannequins are beside a motor scooter inside a display case'. Replace the letter 'l' with 'c' in the sentence.
Example Output: mannequins are beside a motor scooter inside a dispcay case

Example Input: Sentence: 'one wall in the room is flanked by a lovely piece of furniture which displays several object d'art'. Replace the letter 'n' with 'z' in the sentence.
Example Output: oze wall iz the room is flazked by a lovely piece of furziture which displays several object d'art

Example Input: Sentence: 'several cows laying down in a grassy field'. Replace the letter 'a' with 'm' in the sentence.
Example Output:
severml cows lmying down in m grmssy field