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: Some animals, like moles and earthworms spend their entire lives underground. 
Sentence2: Moles reside below the surface so that animal will be protected from a wild fire.

moles