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: when a cooler object touches a warmer object , thermal conduction occurs. 
Sentence2: Heat sink materials are chosen for their high thermal conductivity.

conduction