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.

[EX Q]: Sentence1: air pollution can cause the pH of soil to decrease. 
Sentence2: Acidity is measured with a pH meter or with pH paper strips.
[EX A]: pH

[EX Q]: Sentence1: Algae have varied life cycles. 
Sentence2: And fish eat algae.
[EX A]: Algae

[EX Q]: Sentence1: Another animal that lives within the Marine Biome is a sea tiger. 
Sentence2: Sea tigers must adapt to the salt in the water.
[EX A]:
sea