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: Graphite and diamond are polymorphs of carbon. 
Sentence2: carbon polymorphs are used for making pencil lead.

Answer: carbon


Question: Sentence1: folding an object causes that object to change shape. 
Sentence2: Folding an object causes that object to transform.

Answer: causes


Question: Sentence1: Any population has the potential to produce more offspring than the environment can support. 
Sentence2: Having no natural predators increases potential to produce more offspring than the environment can support.

Answer:
can