In this task, you need to replace a letter in the sentence with another given letter.

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

Sentence: 'a group of giraffe standing on top of a dirt field'. Replace the letter 'a' with 'y' in the sentence.
y group of giryffe stynding on top of y dirt field

Sentence: 'a tall clock tower with trees in the foreground'. Replace the letter 'r' with 'm' in the sentence.

a tall clock towem with tmees in the fomegmound