TASK DEFINITION: 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.
PROBLEM: Sentence: 'a group of people wearing skis and standing at the top of a ski slope'. Reverse all words of length '7' in the given sentence.

SOLUTION: a group of people gniraew skis and standing at the top of a ski slope

PROBLEM: Sentence: 'three people on a tennis court playing tennis'. Reverse all words of length '6' in the given sentence.

SOLUTION: three elpoep on a sinnet court playing sinnet

PROBLEM: Sentence: 'a boy is sitting at a table holding a slice of pizza'. Reverse all words of length '3' in the given sentence.

SOLUTION:
a yob is sitting at a table holding a slice of pizza