TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a polar bear relaxing in a man-made pool'. Replace the letter 'r' with 'x' in the sentence.

SOLUTION: a polax beax xelaxing in a man-made pool

PROBLEM: Sentence: 'a person is riding a skateboard in a skateboard park'. Replace the letter 'a' with 'o' in the sentence.

SOLUTION: o person is riding o skoteboord in o skoteboord pork

PROBLEM: Sentence: 'children wearing baseball uniforms sitting on a bench'. Replace the letter 't' with 'd' in the sentence.

SOLUTION:
children wearing baseball uniforms sidding on a bench