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.

Example Input: Sentence1: Hermit crabs use the shells of dead snails for homes. 
Sentence2: Hermits crabs use dead snails shells as their place to live.
Example Output: Hermit

Example Input: Sentence1: Angiosperm sporophyte is dominant. 
Sentence2: Flowers form on angiosperms.
Example Output: Angiosperm

Example Input: Sentence1: Organisms have to be better adapted as population size increases. 
Sentence2: having no natural predators means organisms have to be better adapted.
Example Output:
Organisms