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: Biomass is the total mass of organisms at a trophic level. 
Sentence2: Biomass is the total mass of living things at a trophic level.

is