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: Limestone caves displaying stalactites. 
Sentence2: Limestone caves are formed by depositions.

Answer: Limestone


Question: Sentence1: poisonous darts are used for defense by sea anemones. 
Sentence2: poisonous darts are used for protection by sea anemones.

Answer: anemones


Question: Sentence1: Most plants grow roots down into the soil to absorb water and minerals. 
Sentence2: After the roots develop, most absorb water and minerals.

Answer:
Most