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: exercise increases a body 's strength. 
Sentence2: Exercise is more than running and lifting.

Answer: exercise


Question: Sentence1: Chordates have a complete digestive system and a closed circulatory system. 
Sentence2: All chordates are vertebrates.

Answer: Chordates


Question: Sentence1: Cancer cells divide more often than normal cells, and grow out of control. 
Sentence2: Chemotherapy and radiotherapy target cells dividing out of control.

Answer:
cells