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

Example Input: Sentence: 'a study features the color green and old-fashioned furniture'. Replace the letter 'e' with 'd' in the sentence.
Example Output: a study fdaturds thd color grddn and old-fashiondd furniturd

Example Input: Sentence: 'street signs hanging next to a traffic light on a city street'. Replace the letter 'g' with 'm' in the sentence.
Example Output: street simns hanminm next to a traffic limht on a city street

Example Input: Sentence: 'several double decker buses along with other cars are traveling down a street'. Replace the letter 'b' with 'g' in the sentence.
Example Output:
several dougle decker guses along with other cars are traveling down a street