instruction:
In this task, you need to replace a letter in the sentence with another given letter.
question:
Sentence: 'a dog with his tongue out riding on a skateboard'. Replace the letter 's' with 'b' in the sentence.
answer:
a dog with hib tongue out riding on a bkateboard


question:
Sentence: 'the cargo train is headed to the next destination'. Replace the letter 'h' with 'x' in the sentence.
answer:
txe cargo train is xeaded to txe next destination


question:
Sentence: 'old, dented rail cars with gang graffiti line a railroad track'. Replace the letter 'a' with 'c' in the sentence.
answer:

old, dented rcil ccrs with gcng grcffiti line c rcilrocd trcck