Definition: Generate an overlapping word between the given two sentences. When you find the overlapping words, they don't have to match exactly, e.g., "survival" and "survive" are valid overlapping words. Little words like "the" or "of" don't count! You must generate significant words which are not the stop words.
Input: Sentence1: Sounds are made by vibrating objects. 
Sentence2: The type of material through which a vibration passes changes the speed at which it travels.

vibrating