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

Example Input: Sentence: 'a herd of cattle standing on a lush green field'. Replace the letter 'g' with 'f' in the sentence.
Example Output: a herd of cattle standinf on a lush freen field

Example Input: Sentence: 'a plate topped with a bacon and broccoli salad'. Replace the letter 'o' with 't' in the sentence.
Example Output: a plate ttpped with a bactn and brtcctli salad

Example Input: Sentence: 'a bowl of pasta with veggies, a second bowl of broccoli and carrots, with a third bowl of fruit'. Replace the letter 'c' with 'q' in the sentence.
Example Output:
a bowl of pasta with veggies, a seqond bowl of broqqoli and qarrots, with a third bowl of fruit