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.
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Question: Sentence1: Ice is frozen water. 
Sentence2: ice expands.

Answer: Ice


Question: Sentence1: Oil and gasoline are fossil fuels. 
Sentence2: lawn mowers convert fossil fuels into motion.

Answer: fossil


Question: Sentence1: irradiating food can be used to kill existing microorganisms in the food. 
Sentence2: Bacterial microorganisms are representative of these biological factors, and e-coli food poisoning is a good example.

Answer:
microorganisms