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.

Sentence: 'a train billowing smoke as it crosses a river by bridge'. Reverse all words of length '1' in the given sentence.
a train billowing smoke as it crosses a river by bridge

Sentence: 'a large bird stands on the ledge of a window'. Reverse all words of length '3' in the given sentence.
a large bird stands on eht ledge of a window

Sentence: 'a group of people are standing playing wii'. Reverse all words of length '3' in the given sentence.
a group of people era standing playing iiw