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: erosion causes a river to become deeper and wider. 
Sentence2: On the contrary, the NILE is the longest river in Africa.

Answer: river


Question: Sentence1: if an object is kicked then force is exerted on that object. 
Sentence2: if an object is kicked then a measurement of newtons is exerted on that object.

Answer: exerted


Question: Sentence1: Chromosomes are coiled structures made of DNA and proteins. 
Sentence2: DNA is deoxyribonucleic acid.

Answer:
DNA