instruction:
In this task, you need to replace a letter in the sentence with another given letter.
question:
Sentence: 'a couple of white street signs sitting on top of a pole'. Replace the letter 'n' with 't' in the sentence.
answer:
a couple of white street sigts sittitg ot top of a pole


question:
Sentence: 'a bathroom that has  a sink and a toilet'. Replace the letter 's' with 'a' in the sentence.
answer:
a bathroom that haa  a aink and a toilet


question:
Sentence: 'the two zebras standing out in the field'. Replace the letter 'h' with 'i' in the sentence.
answer:

tie two zebras standing out in tie field