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.

[EX Q]: Sentence: 'a couple of toothbrushes that are on a towel'. Reverse all words of length '6' in the given sentence.
[EX A]: a elpuoc of toothbrushes that are on a towel

[EX Q]: Sentence: 'a blue sign sitting on the side of a road next to a tree'. Reverse all words of length '1' in the given sentence.
[EX A]: a blue sign sitting on the side of a road next to a tree

[EX Q]: Sentence: 'a train station with a green chain on the tracks and children waiting for it to go by'. Reverse all words of length '1' in the given sentence.
[EX A]:
a train station with a green chain on the tracks and children waiting for it to go by