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: Angiosperm sporophyte is dominant. 
Sentence2: Flowers form on angiosperms.

A: Angiosperm
****
Q: Sentence1: All life relies on a relatively narrow range of pH, or acidity. 
Sentence2: humans rely on a relatively narrow range of acidity.

A: acidity
****
Q: Sentence1: All plants are eukaryotes. 
Sentence2: Viruses are not plants.

A:
plants
****