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: For test cylinders without graduation marks, a manual calibration method has to be used. 
Sentence2: graduation markings are used to measure the volume of a liquid.

marks