TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a yellow street sign sitting on the side of a road'. Replace the letter 'a' with 'd' in the sentence.

SOLUTION: d yellow street sign sitting on the side of d rodd

PROBLEM: Sentence: 'a sign sitting on the side of a snow covered slope'. Replace the letter 'e' with 'g' in the sentence.

SOLUTION: a sign sitting on thg sidg of a snow covgrgd slopg

PROBLEM: Sentence: 'a hand holding a toothbrush is near a cat on a bed'. Replace the letter 'o' with 'm' in the sentence.

SOLUTION:
a hand hmlding a tmmthbrush is near a cat mn a bed