Definition: 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.
Input: Sentence: 'men playing soccer while the referee wearing black and yellow watches them'. Reverse all words of length '7' in the given sentence.

men gniyalp soccer while the eerefer gniraew black and yellow sehctaw them