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 close up of the front of a train on train tracks'. Reverse all words of length '3' in the given sentence.

SOLUTION: a close up of eht front of a train on train tracks

PROBLEM: Sentence: 'a young boy plays with a phone sitting on the ground'. Reverse all words of length '6' in the given sentence.

SOLUTION: a young boy plays with a phone sitting on the dnuorg

PROBLEM: Sentence: 'sheep are in a field overlooking a valley'. Reverse all words of length '2' in the given sentence.

SOLUTION:
sheep are ni a field overlooking a valley