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 close up of the front of a train on train tracks'. Reverse all words of length '3' in the given sentence.
[EX A]: a close up of eht front of a train on train tracks

[EX Q]: Sentence: 'someone is sitting on a elephant and messing with the seat'. Reverse all words of length '7' in the given sentence.
[EX A]: enoemos is gnittis on a elephant and gnissem with the seat

[EX Q]: Sentence: 'this is a bunch of signs in an alley'. Reverse all words of length '4' in the given sentence.
[EX A]:
siht is a bunch of signs in an alley