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

Sentence: 'a zebra is eating hay in a fenced enclosure'. Replace the letter 'e' with 'i' in the sentence.
a zibra is iating hay in a fincid inclosuri

Sentence: 'a book shelf full of books and nick nacks '. Replace the letter 'o' with 'm' in the sentence.
a bmmk shelf full mf bmmks and nick nacks 

Sentence: 'a man is riding on a skateboard with four wheels'. Replace the letter 'e' with 'a' in the sentence.

a man is riding on a skataboard with four whaals