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

Sentence: 'closeup of two teddy bears in red scarves and a brown teddy bear'. Replace the letter 'i' with 'y' in the sentence.
closeup of two teddy bears yn red scarves and a brown teddy bear

Sentence: 'a yellow fire hydrant sitting on the sidewalk'. Replace the letter 'o' with 'd' in the sentence.
a yelldw fire hydrant sitting dn the sidewalk

Sentence: 'a horse running through a field of grass'. Replace the letter 'a' with 'o' in the sentence.

o horse running through o field of gross