instruction:
In this task, you need to replace a letter in the sentence with another given letter.
question:
Sentence: 'a bike sitting parked next to a cart in front of some boxes'. Replace the letter 't' with 'x' in the sentence.
answer:
a bike sixxing parked nexx xo a carx in fronx of some boxes

question:
Sentence: 'a hipster riding a skateboard up the side of a wall'. Replace the letter 's' with 'm' in the sentence.
answer:
a hipmter riding a mkateboard up the mide of a wall

question:
Sentence: 'an inquiring elephant wonders if there is a treat at hand'. Replace the letter 't' with 'q' in the sentence.
answer:
an inquiring elephanq wonders if qhere is a qreaq aq hand