In this task, you need to remove 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 mountain towers over a train going down the tracks'. Remove all words of length '4' in the given sentence.
a mountain towers a train going the tracks

Sentence: 'a fire hydrant sits off a city street'. Remove all words of length '4' in the given sentence.
a hydrant off a street

Sentence: 'a man wearing a suit and tie walking down the street'. Remove all words of length '6' in the given sentence.

a man wearing a suit and tie walking down the