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: Passive immunity lasts only as long as the antibodies survive in body fluids. 
Sentence2: A pregnant woman will pass antibodies to the fetus.

Answer: antibodies


Question: Sentence1: melting is when solids are heated above their melting point. 
Sentence2: Ice is a solid, it's cold and it's hard.

Answer: solids


Question: Sentence1: infection can cause bodily tissues to swell. 
Sentence2: HIV infection is a chronic lifelong infection.

Answer:
infection