TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a young man playing tennis and preparing to hit the ball'. Replace the letter 'e' with 'c' in the sentence.

SOLUTION: a young man playing tcnnis and prcparing to hit thc ball

PROBLEM: Sentence: 'a herd of zebra stand together and eat grass'. Replace the letter 'n' with 'r' in the sentence.

SOLUTION: a herd of zebra stard together ard eat grass

PROBLEM: Sentence: 'an airliner is sitting on the tarmac on a cloudy day'. Replace the letter 't' with 'g' in the sentence.

SOLUTION:
an airliner is sigging on ghe garmac on a cloudy day