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 baseball player swinging a bat at a ball'. Replace the letter 's' with 'n' in the sentence.

SOLUTION: a baneball player nwinging a bat at a ball

PROBLEM: Sentence: 'a professional tennis player leaping for the ball'. Replace the letter 'e' with 'g' in the sentence.

SOLUTION:
a profgssional tgnnis playgr lgaping for thg ball