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.

[EX Q]: Sentence1: Light source is an ultra-bright, unbreakable LED Bulb. 
Sentence2: LEDs convert electricity into light and heat energy.
[EX A]: LED

[EX Q]: Sentence1: a flashlight converts chemical energy into light energy. 
Sentence2: Chemical energy converted to light energy requires batteries.
[EX A]: chemical

[EX Q]: Sentence1: an animal requires nutrients for survival. 
Sentence2: Potassium is an essential nutrient for plants and animals.
[EX A]:
nutrients