instruction:
In this task, you need to replace a letter in the sentence with another given letter.
question:
Sentence: 'there is a piece of a cake on the plate and a cup of drink'. Replace the letter 'r' with 'u' in the sentence.
answer:
theue is a piece of a cake on the plate and a cup of duink


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


question:
Sentence: 'a couple of large pieces of equipment and rail cars next to a railroad track'. Replace the letter 'r' with 'w' in the sentence.
answer:

a couple of lawge pieces of equipment and wail caws next to a wailwoad twack