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: Basically the process is pretty simple. 
Sentence2: All cells share some of the same structures and simple processes.

Answer: process


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

Answer: lightning


Question: Sentence1: Adult tunicates are barrel-shaped. 
Sentence2: Urochordates are commonly called tunicates.

Answer:
tunicates