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: Male dogs use pheromones in urine to mark their territory. 
Sentence2: Pheromones are hormones that are thought to stimulate, through smell, sexual reactions in animals.

A: pheromones
****
Q: Sentence1: when a body of water receives more water than it can hold , a flood occurs. 
Sentence2: Floods are deadly, floods are devastating.

A: flood
****
Q: Sentence1: Smog contains particulates. 
Sentence2: Particulates are matter suspended in air.

A:
particulates
****