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

Sentence: 'a young boy riding his skateboard down the sidewalk'. Replace the letter 'd' with 'p' in the sentence.
a young boy riping his skateboarp pown the sipewalk

Sentence: 'an older red airplane is going straight up'. Replace the letter 'h' with 'z' in the sentence.
an older red airplane is going straigzt up

Sentence: 'a small bird perched on a open window'. Replace the letter 'e' with 'r' in the sentence.

a small bird prrchrd on a oprn window