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: 'an image of a group of people sitting in the snow'. Reverse all words of length '6' in the given sentence.
an image of a group of elpoep sitting in the snow

Sentence: 'two giraffes with beautiful markings are shown from behind'. Reverse all words of length '8' in the given sentence.
two seffarig with beautiful sgnikram are shown from behind

Sentence: 'a black dog laying in front of the bench cheering a stick'. Reverse all words of length '1' in the given sentence.

a black dog laying in front of the bench cheering a stick