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

Sentence: 'a woman is standing on a street curb'. Replace the letter 'a' with 't' in the sentence.
t womtn is sttnding on t street curb

Sentence: 'a open entrance leading to a set of closed doors'. Replace the letter 'd' with 'f' in the sentence.
a open entrance leafing to a set of closef foors

Sentence: 'a large crowd at a park with some flying fancy shaped kites'. Replace the letter 'd' with 'y' in the sentence.

a large crowy at a park with some flying fancy shapey kites