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 bunch of umbrellas are up in the air'. Reverse all words of length '9' in the given sentence.
a bunch of sallerbmu are up in the air

Sentence: 'a surfer on wave in open water wearing a wet suit'. Reverse all words of length '7' in the given sentence.
a surfer on wave in open water gniraew a wet suit

Sentence: 'two pedestrians are crossing the intersection amongst repair work'. Reverse all words of length '7' in the given sentence.

two pedestrians are crossing the intersection tsgnoma repair work