TASK DEFINITION: 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.
PROBLEM: Sentence1: All life relies on a relatively narrow range of pH, or acidity. 
Sentence2: humans rely on a relatively narrow range of acidity.

SOLUTION: acidity

PROBLEM: Sentence1: Annelids have the amazing capacity to regrow segments that break off. 
Sentence2: Earthworms can regrow segments that break off.

SOLUTION: break

PROBLEM: Sentence1: Humans have collected and grown mushrooms for food for thousands of years. 
Sentence2: Mushrooms are an example of fungi.

SOLUTION:
mushrooms