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: cell division often causes growth. 
Sentence2: Mitosis is cell division.

Answer: cell


Question: Sentence1: if a habitat can no longer support animals then those animals will move to another area. 
Sentence2: Each species of animal is unique.

Answer: animals


Question: Sentence1: sunlight and rain can cause a rainbow. 
Sentence2: Cold fronts can cause a rainbow.

Answer:
rainbow