instruction:
In this task, you need to replace a letter in the sentence with another given letter.
question:
Sentence: 'a man sitting on a luggage cart inside of an airport'. Replace the letter 't' with 'a' in the sentence.
answer:
a man siaaing on a luggage cara inside of an airpora

question:
Sentence: 'a giraffe standing alone with a low fence behind it'. Replace the letter 't' with 'o' in the sentence.
answer:
a giraffe soanding alone wioh a low fence behind io

question:
Sentence: 'a man playing a game of frisbee with two brown dogs'. Replace the letter 'a' with 'x' in the sentence.
answer:
x mxn plxying x gxme of frisbee with two brown dogs