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: Bees feed on nectar and pollen. 
Sentence2: Plant reproduction often requires bees and nectar.

Answer: Bees


Question: Sentence1: Plants that shed their leaves seasonally each year are called deciduous plants. 
Sentence2: vines shed their leaves seasonally each year.

Answer: each


Question: Sentence1: Dogs, of course, are mammals. 
Sentence2: Playing is one way dogs learn how to behave.

Answer:
Dogs