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: Soil Erosion Soil erosion is a natural process. 
Sentence2: wind and rain is a natural process.

Answer: natural


Question: Sentence1: Very often their only metal object in the house is a cooking pot or a knife. 
Sentence2: sharpening a knife causes it to change shape.

Answer: knife


Question: Sentence1: Sex hormones are chemical messengers that control sexual development and reproduction. 
Sentence2: Sex hormones are chemical messengers in male and female bodies.

Answer:
Sex