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: Specialization decreases mortality 12,13 and increases survival. 
Sentence2: evolving different adaptations increases survival.

Answer: increases


Question: Sentence1: a battery converts chemical energy into electrical energy. 
Sentence2: Battery electricity comes conversion.

Answer: battery


Question: Sentence1: some animals' fur grows thicker for staying warm in the winter. 
Sentence2: Mammals are animals that are born with fur or hair.

Answer:
animals'