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.
Input: Sentence: 'collectible bears on display in costumes and the year they were released'. Reverse all words of length '7' in the given sentence.

collectible bears on yalpsid in costumes and the year they were released