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 being towed behind a boat on a board'. Reverse all words of length '4' in the given sentence.
a man being towed behind a taob on a board

Sentence: 'an elephant is standing in the road by the truck'. Reverse all words of length '5' in the given sentence.
an elephant is standing in the road by the kcurt

Sentence: 'several ties are hung up near some lockers'. Reverse all words of length '2' in the given sentence.

several ties are hung pu near some lockers