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: Nonmetal elements are far fewer in number. 
Sentence2: There are 17 nonmetals on the periodic table.

Answer: Nonmetal


Question: Sentence1: Scientists still know relatively little about Archaea. 
Sentence2: scientists still know relatively little about non-bacterial prokaryotes.

Answer: Scientists


Question: Sentence1: an earthquake causes the ground to shake. 
Sentence2: Earthquakes cause damage to man-made structures.

Answer:
causes