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: Coral reefs provide food and shelter to many ocean organisms. 
Sentence2: Coral Reefs Coral reefs are threatened.

A: Coral
****
Q: Sentence1: high pressure systems cause clear weather. 
Sentence2: Weather Clear weather usually means good visibility.

A: clear
****
Q: Sentence1: Male dogs use pheromones in urine to mark their territory. 
Sentence2: During Urination Dog's urine is used as a scent marker for other dogs.

A:
urine
****