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.

Example Input: Sentence1: Insects spread disease and destroy crops. 
Sentence2: Crops are plants that are grown for food or other uses.
Example Output: crops

Example Input: Sentence1: when electricity flows to a light bulb , the light bulb will turn on. 
Sentence2: water pumps can turn on light bulbs.
Example Output: bulb

Example Input: Sentence1: Antibiotics Chlamydial infections are treated with an antibiotic. 
Sentence2: Something that can treat Chlamydial infections have no effect on viruses.
Example Output:
Chlamydial