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: Cancer is a disease in which cells divide out of control. 
Sentence2: Cancer is a disease in which cells grow and divide rapidly.

Answer: Cancer


Question: Sentence1: a fire requires oxygen to burn. 
Sentence2: If the oxygen is removed, the fire is smothered.

Answer: oxygen


Question: Sentence1: Cars are vehicles and trucks are vehicles. 
Sentence2: A driver feeds feedback on the speed of their car with a speedometer.

Answer:
Cars