In this task, you need to replace a letter in the sentence with another given letter.

Sentence: 'a cat sits on the floor next to a purse'. Replace the letter 'a' with 'b' in the sentence.
b cbt sits on the floor next to b purse

Sentence: 'a suitcase is sitting on a sidewalk near trees'. Replace the letter 's' with 'd' in the sentence.
a duitcade id ditting on a didewalk near treed

Sentence: 'one person is on the phone, another person is holding a frozen drink'. Replace the letter 'r' with 'g' in the sentence.

one pegson is on the phone, anotheg pegson is holding a fgozen dgink