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.
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Question: 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.

Answer: 5

Question: Sentence1: An example of a cartilaginous fish is a shark.
Sentence2: jaws make sharks excellent predators.

Answer: shark

Question: Sentence1: Mollusks are a major food source for other organisms, including humans.
Sentence2: Many organisms are omnivores with variable diets.

Answer:
organisms