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: 'an openair tour bus driving in a city'. Reverse all words of length '7' in the given sentence.
Example Output: an rianepo tour bus gnivird in a city

Example Input: Sentence: 'multiple people shopping around the farmers market during the day'. Reverse all words of length '6' in the given sentence.
Example Output: multiple elpoep shopping dnuora the farmers tekram gnirud the day

Example Input: Sentence: 'a white horse with black spots leaning down to eat grass'. Reverse all words of length '2' in the given sentence.
Example Output:
a white horse with black spots leaning down ot eat grass