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: Mating is generally preceded by courtship. 
Sentence2: Mating is generally similar across species.

Answer: Mating


Question: Sentence1: if an object is black then that object absorbs all visible light. 
Sentence2: Something is black if it absorbs visible light and doesn't reflect.

Answer: light


Question: Sentence1: hunting requires seeing prey. 
Sentence2: Vision is our ability to see.

Answer:
seeing