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

Sentence: 'a man on a horse in riding gear looking onward'. Replace the letter 'o' with 'h' in the sentence.
a man hn a hhrse in riding gear lhhking hnward

Sentence: 'a person jumping up in the air on a snowboard'. Replace the letter 'r' with 'o' in the sentence.
a peoson jumping up in the aio on a snowboaod

Sentence: 'a baby is using a toothbrush to brush his teeth'. Replace the letter 'b' with 'p' in the sentence.

a papy is using a toothprush to prush his teeth