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: 'a small plane sitting on top of a tarmac'. Reverse all words of length '2' in the given sentence.

SOLUTION: a small plane sitting no top fo a tarmac

PROBLEM: Sentence: 'a filed full of lush green trees and grass'. Reverse all words of length '4' in the given sentence.

SOLUTION:
a filed lluf of hsul green trees and grass