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

Sentence: 'a young baseball player throws the ball as others watch'. Replace the letter 'a' with 'n' in the sentence.
n young bnsebnll plnyer throws the bnll ns others wntch

Sentence: 'a refrigerator with both its doors open in a kitchen'. Replace the letter 'o' with 'x' in the sentence.
a refrigeratxr with bxth its dxxrs xpen in a kitchen

Sentence: 'a crowd of people standing and sitting beside a lake full of little boats'. Replace the letter 'r' with 'b' in the sentence.

a cbowd of people standing and sitting beside a lake full of little boats