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: Metabolic rate is the rate at which food is burned for energy. 
Sentence2: thyroid hormones increase the rate of energy consumption.

Answer: energy


Question: Sentence1: Mammals that are viviparous are called therian mammals. 
Sentence2: Mouse-sized viviparous mammals evolved by Jurassic times.

Answer: Mammals


Question: Sentence1: Stimuli are detected by sensory nerve cells. 
Sentence2: CN II , the optic nerve , is also a sensory nerve.

Answer:
sensory