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: Amphibians begin their lives in the water. 
Sentence2: animals that begin their lives in water breathe with gills then move elsewhere breathe with lungs.

lives