TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'an overhead view of a city cross walk on a rainy day features an array of colorful umbrellas'. Replace the letter 's' with 'd' in the sentence.

SOLUTION: an overhead view of a city crodd walk on a rainy day featured an array of colorful umbrellad

PROBLEM: Sentence: 'a baseball player is throwing a ball across the dirt field'. Replace the letter 'a' with 't' in the sentence.

SOLUTION: t btsebtll pltyer is throwing t btll tcross the dirt field

PROBLEM: Sentence: 'an image of a family of white bears at the zoo'. Replace the letter 'w' with 'u' in the sentence.

SOLUTION:
an image of a family of uhite bears at the zoo