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 group of people sitting on a wooden bench'. Reverse all words of length '1' in the given sentence.
a group of people sitting on a wooden bench

Sentence: 'a city truck two city buses and a yellow fire hydrant'. Reverse all words of length '4' in the given sentence.
a ytic truck two ytic buses and a yellow erif hydrant

Sentence: 'a man relaxes on a bed in a small room'. Reverse all words of length '7' in the given sentence.

a man sexaler on a bed in a small room