TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'street sign titled kittery maine state line in green'. Replace the letter 'e' with 'r' in the sentence.

SOLUTION: strrrt sign titlrd kittrry mainr statr linr in grrrn

PROBLEM: Sentence: 'adult man on grassy field playing disc game'. Replace the letter 'n' with 'l' in the sentence.

SOLUTION: adult mal ol grassy field playilg disc game

PROBLEM: Sentence: 'many piles of produce are underneath sale signs'. Replace the letter 'n' with 'r' in the sentence.

SOLUTION:
mary piles of produce are urderreath sale sigrs