TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'two children who are standing next to a white fire hydrant'. Replace the letter 't' with 'r' in the sentence.

SOLUTION: rwo children who are sranding nexr ro a whire fire hydranr

PROBLEM: Sentence: 'a dog laying in front of a horses stall with the horse peeking over the half door'. Replace the letter 'a' with 'b' in the sentence.

SOLUTION: b dog lbying in front of b horses stbll with the horse peeking over the hblf door

PROBLEM: Sentence: 'a woman catches a wave on a surfboard'. Replace the letter 'u' with 'w' in the sentence.

SOLUTION:
a woman catches a wave on a swrfboard