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

Sentence: 'three colorful knit bear toys with button eyes'. Replace the letter 'r' with 'z' in the sentence.
thzee colozful knit beaz toys with button eyes

Sentence: 'a gray and white cat sleeping on top of a laptop computer'. Replace the letter 'l' with 'g' in the sentence.
a gray and white cat sgeeping on top of a gaptop computer

Sentence: 'an old tractor is sitting in the overgrowth'. Replace the letter 'a' with 'n' in the sentence.

nn old trnctor is sitting in the overgrowth