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

Sentence: 'a man is standing on a snowboard, atop a mountain'. Replace the letter 'd' with 'u' in the sentence.
a man is stanuing on a snowboaru, atop a mountain

Sentence: 'a man is somewhat hard to be seen in the wave, on his board'. Replace the letter 's' with 'b' in the sentence.
a man ib bomewhat hard to be been in the wave, on hib board

Sentence: 'three people stand in front of the giraffe zoo section'. Replace the letter 'h' with 'e' in the sentence.
teree people stand in front of tee giraffe zoo section