instruction:
In this task, you need to replace a letter in the sentence with another given letter.
question:
Sentence: 'an umbrella sitting on top of a hill next to a body of water'. Replace the letter 't' with 'b' in the sentence.
answer:
an umbrella sibbing on bop of a hill nexb bo a body of waber


question:
Sentence: 'a memorial with various plaques and american flags on it'. Replace the letter 'a' with 'k' in the sentence.
answer:
k memorikl with vkrious plkques knd kmerickn flkgs on it


question:
Sentence: 'a cat is sitting on the floor next to a workstation'. Replace the letter 'n' with 'r' in the sentence.
answer:

a cat is sittirg or the floor rext to a workstatior