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: Parasites are organisms that live off a host. 
Sentence2: roundworms may be free-living or live off a host.

Answer: host


Question: Sentence1: Balance is the ability to sense and maintain body position. 
Sentence2: Another part of the inner ear is used for balance.

Answer: Balance


Question: Sentence1: disease has a negative impact on an organism. 
Sentence2: Smoking was negatively associated with prevalent Alzheimer's disease and dementia.

Answer:
disease