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

SOLUTION: break

PROBLEM: Sentence1: Dams are very damaging to rivers. 
Sentence2: Creating a lake can be very damaging to rivers.

SOLUTION: damaging

PROBLEM: Sentence1: Another group of echinoderms are the echinoids. 
Sentence2: Echinoids have unique water vascular system was tube feet.

SOLUTION:
echinoids