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

Sentence: 'a zebra standing by a pile of large rocks'. Replace the letter 'i' with 'x' in the sentence.
a zebra standxng by a pxle of large rocks

Sentence: 'a man extends his arm with a frisbee in hand as another reaches to grab it while teammates watch'. Replace the letter 'a' with 'g' in the sentence.
g mgn extends his grm with g frisbee in hgnd gs gnother regches to grgb it while tegmmgtes wgtch

Sentence: 'a cat is peeping out from under a blanket'. Replace the letter 'i' with 'b' in the sentence.

a cat bs peepbng out from under a blanket