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.

[Q]: Sentence: 'a person parasails in water with mountains in the background'. Reverse all words of length '4' in the given sentence.
[A]: a person parasails in water htiw mountains in the background


[Q]: Sentence: 'a person in bear feet standing on a skateboard'. Reverse all words of length '4' in the given sentence.
[A]: a person in raeb teef standing on a skateboard


[Q]: Sentence: 'there are three traffic lights at an intersection'. Reverse all words of length '12' in the given sentence.
[A]:
there are three traffic lights at an noitcesretni