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: Most copepods feed on phytoplankton. 
Sentence2: most copepods feed on bacteria and algae that use sunlight to make food.

A: copepods
****
Q: Sentence1: All oaks are trees. 
Sentence2: Cutting down oaks has a negative impact on an ecosystem.

A: oaks
****
Q: Sentence1: WEATHERING -- Deterioration, decay or damage caused by exposure to the elements. 
Sentence2: glaciers can cause damage.

A:
damage
****