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: Carbon cycles quickly between organisms and the atmosphere. 
Sentence2: the atmosphere is essential to all living organisms.
[EX A]: organisms

[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: Biofuels include ethanol, methanol, biodiesel, biocrude, and methane. 
Sentence2: methane produces electricity when burned.
[EX A]:
methane