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

A: cell
****
Q: Sentence1: To keep cut flowers lasting longer, use a commercial florist preservative such as Floralife. 
Sentence2: Dehydrating food is used to make it last longer.

A: lasting
****
Q: Sentence1: Courtship is behavior that is intended to attract a mate. 
Sentence2: Courtship can be manifested by displays of color.

A:
Courtship
****