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.

[Q]: Sentence1: Coral reefs provide food and shelter to many ocean organisms. 
Sentence2: Coral Reefs Coral reefs are threatened.
[A]: Coral


[Q]: Sentence1: infection can cause bodily tissues to swell. 
Sentence2: Bacteria can cause bodily tissues to swell.
[A]: bodily


[Q]: Sentence1: Scientists still know relatively little about Archaea. 
Sentence2: Acetate kinase is found in microbes of the bacteria and archaea domains.
[A]:
Archaea