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: condensation is when change from a gas into a liquid by reducing heat energy. 
Sentence2: Condensation is the reverse of vaporization , or change from liquid to gas.

gas