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.

Sentence: 'a man laying on a bench and a woman next to him touching his face'. Reverse all words of length '4' in the given sentence.
a man laying on a bench and a woman txen to him touching his ecaf

Sentence: 'several vehicles at a traffic stop on a small downtown street'. Reverse all words of length '4' in the given sentence.
several vehicles at a traffic pots on a small downtown street

Sentence: 'a bunch of zebras are standing on the side of a dirt road'. Reverse all words of length '8' in the given sentence.
a bunch of zebras are gnidnats on the side of a dirt road