TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a man stands next to a basketball as it sits on the floor'. Replace the letter 'n' with 'o' in the sentence.

SOLUTION: a mao staods oext to a basketball as it sits oo the floor

PROBLEM: Sentence: 'a box of a dozen doughnuts all varieties'. Replace the letter 'l' with 'i' in the sentence.

SOLUTION: a box of a dozen doughnuts aii varieties

PROBLEM: Sentence: 'someone playing football on a football field'. Replace the letter 'b' with 'r' in the sentence.

SOLUTION:
someone playing footrall on a footrall field