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: Muscles can only contract. 
Sentence2: Contraction is a type of movement.

Answer: contract


Question: Sentence1: Basically, heat is energy. 
Sentence2: Head hair is especially important in preventing energy loss from the body.

Answer: energy


Question: Sentence1: rest has a positive impact on a health. 
Sentence2: Rest can include sleep as well as sitting and resting.

Answer:
rest