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.

Sentence1: if an animal lives under ground then that animal will be protected from a wild fire.
Sentence2: animals that live under ground in California will be protected from some natural disasters.
animal

Sentence1: Acid rain is precipitation which pH is 5.7 or lower.
Sentence2: gases from burning coal causes precipitation which pH is 5.7 or lower.
5

Sentence1: Fungi are the only organisms that can decompose wood.
Sentence2: Mushrooms are organisms known as fungi.
Fungi