TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a girl riding a horse is jumping the log'. Replace the letter 'a' with 't' in the sentence.

SOLUTION: t girl riding t horse is jumping the log

PROBLEM: Sentence: 'a gray and white cat sleeping on top of a laptop computer'. Replace the letter 'l' with 'g' in the sentence.

SOLUTION: a gray and white cat sgeeping on top of a gaptop computer

PROBLEM: Sentence: 'a man cutting into a chocolate cake while friends look on'. Replace the letter 'm' with 'w' in the sentence.

SOLUTION:
a wan cutting into a chocolate cake while friends look on