In this task, you need to reverse all words of a given length in the sentence. The number of letters in a word determine its length. For example, the length of the word "apple" is 5.

Example Input: Sentence: 'the cox is standing behind the fence alone'. Reverse all words of length '2' in the given sentence.
Example Output: the cox si standing behind the fence alone

Example Input: Sentence: 'a man trying to hit a ball that is close to the ground'. Reverse all words of length '1' in the given sentence.
Example Output: a man trying to hit a ball that is close to the ground

Example Input: Sentence: 'a bus on the side of the street'. Reverse all words of length '4' in the given sentence.
Example Output:
a bus on the edis of the street