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: mineral graphite is used for making pencil lead. 
Sentence2: Diamond and graphite are made of carbon.

Answer: graphite


Question: Sentence1: a fire requires oxygen to burn. 
Sentence2: A fire requires something with exactly eight protons to burn.

Answer: burn


Question: Sentence1: conserving water can be used for survival in a dry environment. 
Sentence2: Many plants have developed unique leaf adaptations in order to conserve water.

Answer:
conserving