TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a herd of cattle standing on a lush green field'. Replace the letter 'g' with 'f' in the sentence.

SOLUTION: a herd of cattle standinf on a lush freen field

PROBLEM: Sentence: 'a boy is sitting at a dinner table with his food'. Replace the letter 't' with 'r' in the sentence.

SOLUTION: a boy is sirring ar a dinner rable wirh his food

PROBLEM: Sentence: 'two giraffe standing in an enclosure at the zoo next to a  tree'. Replace the letter 'n' with 'g' in the sentence.

SOLUTION:
two giraffe stagdigg ig ag egclosure at the zoo gext to a  tree