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: Terrestrial arthropods have an excretory system that conserves water and eliminates waste. 
Sentence2: Some animals have excretory structures that conserve water and elminate waste.

waste