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: Instead, the body is covered with a protective shell of bony armor. 
Sentence2: Most mollusks have protective of bony armor.
[EX A]: armor

[EX Q]: Sentence1: if soil is permeable then water easily flows through that soil. 
Sentence2: Ice forming and expanding in soil allows water to easily flow through that soil.
[EX A]:
easily