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

Sentence: 'a large elephant that has people all around it'. Replace the letter 'h' with 'm' in the sentence.
a large elepmant tmat mas people all around it

Sentence: 'a train traveling through a dark tunnel next to green brush.'. Replace the letter 'r' with 'e' in the sentence.
a teain teaveling theough a daek tunnel next to geeen beush.

Sentence: 'a snow covered mountain surrounded by a forest'. Replace the letter 's' with 'p' in the sentence.

a pnow covered mountain purrounded by a forept