instruction:
In this task, you need to replace a letter in the sentence with another given letter.
question:
Sentence: 'a mouse and keyboard sitting on a wooden desk'. Replace the letter 'a' with 'n' in the sentence.
answer:
n mouse nnd keybonrd sitting on n wooden desk


question:
Sentence: 'a long green grain traveling past a white building'. Replace the letter 'w' with 'o' in the sentence.
answer:
a long green grain traveling past a ohite building


question:
Sentence: 'giraffes in a field with trees and tall grass'. Replace the letter 'e' with 'a' in the sentence.
answer:

giraffas in a fiald with traas and tall grass