TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a geoup of people on bicycles coming down a street'. Replace the letter 'i' with 'x' in the sentence.

SOLUTION: a geoup of people on bxcycles comxng down a street

PROBLEM: Sentence: 'a white plate topped with a cut in half sandwich'. Replace the letter 'o' with 'x' in the sentence.

SOLUTION: a white plate txpped with a cut in half sandwich

PROBLEM: Sentence: 'a ferret sniffing the receiver of a telephone'. Replace the letter 'g' with 't' in the sentence.

SOLUTION:
a ferret sniffint the receiver of a telephone