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 skiers standing at the base of a mountain'. Reverse all words of length '3' in the given sentence.

SOLUTION: a group of skiers standing at eht base of a mountain

PROBLEM: Sentence: 'the tour buses are driving away from the building'. Reverse all words of length '5' in the given sentence.

SOLUTION: the tour sesub are driving away from the building

PROBLEM: Sentence: 'a large long train on a steel track'. Reverse all words of length '2' in the given sentence.

SOLUTION:
a large long train no a steel track