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: All monkeys are mammals. 
Sentence2: monkeys conserve body heat with their hair or fur.

Answer: monkeys


Question: Sentence1: Some birds are pollinators that co-evolved with plants. 
Sentence2: insects pollinate plants.

Answer: plants


Question: Sentence1: Otters fur is the thickest fur of any animal. 
Sentence2: otters can be used to make clothing for keeping warm.

Answer:
Otters