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.

[EX Q]: Sentence1: Polyps usually reproduce asexually. 
Sentence2: Polyps usually reproduce several different ways.
[EX A]: Polyps

[EX Q]: Sentence1: Some pelycosaurs gave rise to a group of animals called therapsids. 
Sentence2: Like most other groups of synapsids, all pelycosaurs are now extinct.
[EX A]: pelycosaurs

[EX Q]: Sentence1: staying warm has a positive impact on an animal 's survival. 
Sentence2: Warmth has a positive impact on mans survival.
[EX A]:
impact