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 switch is used to start the flow of current in an electrical circuit. 
Sentence2: Each switch is moved up for on, and down for off.

switch