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: Mitosis is cell division. 
Sentence2: mitosis often causes growth.

A: Mitosis
****
Q: Sentence1: Polyps usually reproduce asexually. 
Sentence2: Polyps usually reproduce several different ways.

A: Polyps
****
Q: Sentence1: microorganisms can cause infections. 
Sentence2: Chlorination uses liquid chlorine bleach to kill microorganisms.

A:
microorganisms
****