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: a thermometer is used to measure temperature. 
Sentence2: a thermometer is used to measure heat.
[EX A]: a

[EX Q]: Sentence1: Most fungi get organic compounds from dead organisms. 
Sentence2: Moulds, yeasts, rusts, smuts, mildews, and mushrooms are all types of fungi.
[EX A]: fungi

[EX Q]: Sentence1: the vanes rotating in an electric fan causes air to move. 
Sentence2: Air is mostly nitrogen and oxygen.
[EX A]:
air