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: a gasoline lawn mower converts gasoline into motion. 
Sentence2: Machines mow down forests much as a lawn mower cuts grass.

lawn