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: Digestion is the process of breaking down food into components the body can absorb. 
Sentence2: Saliva starts to break down the food.

A: breaking
****
Q: Sentence1: Humans have collected and grown mushrooms for food for thousands of years. 
Sentence2: humans have collected and grown porcinis for thousands of years.

A: Humans
****
Q: Sentence1: Amphibians have sense organs to smell and taste chemicals. 
Sentence2: Smell and taste belong to our chemical sensing system.

A:
smell
****