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Advantages of cluster randomised controlled trials over individually randomised controlled trials include the ability to study interventions that can not be directed toward selected individuals ( e.g. , a radio show about lifestyle changes ) and the ability to control for " contamination " across individuals ( e.g. , one individual 's changing behaviors may influence another individual to do so ) .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
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