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: 'three zebras are standing on a grassy field'. Reverse all words of length '1' in the given sentence.
three zebras are standing on a grassy field

Sentence: 'a very large truck with people in back on a city street'. Reverse all words of length '6' in the given sentence.
a very large truck with elpoep in back on a city teerts

Sentence: 'a couch chair and coffee table in a sitting area'. Reverse all words of length '7' in the given sentence.

a couch chair and coffee table in a gnittis area