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: 'there are many animals standing on the top of this mountain'. Reverse all words of length '4' in the given sentence.
there are ynam animals standing on the top of siht mountain

Sentence: 'a bus with lots of big tires sitting parked on a street'. Reverse all words of length '6' in the given sentence.
a bus with lots of big tires sitting dekrap on a teerts

Sentence: 'a group of people ski down a mountain slope'. Reverse all words of length '8' in the given sentence.

a group of people ski down a niatnuom slope