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: smell is used for finding food by some animals. 
Sentence2: Food includes small rodents and birds.

Answer: food


Question: Sentence1: lightning can cause a forest fire. 
Sentence2: Lightning can cause a natural cycle in forests.

Answer: lightning


Question: Sentence1: All plants are of bush type. 
Sentence2: some birds are pollinators that co-evolved with bushes.

Answer:
bush