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: Biologists use microscopes to study things that are too small to be seen with the unaided eye. 
Sentence2: Biologists study small things that can't normally be seen with an unaided eye.

eye