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.
--------
Question: Sentence1: a switch is used to start the flow of current in an electrical circuit. 
Sentence2: The flow of electrical current powers a light bulb.

Answer: current


Question: Sentence1: Coral Reefs Coral reefs are widely distributed in warm shallow waters. 
Sentence2: warm shallow waters provide food and shelter to many ocean organisms.

Answer: shallow


Question: Sentence1: For adolescents, ages 12-18. 
Sentence2: ages 12-18 is a time of significant mental, emotional, and social changes.

Answer:
12-18