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The United States Geological Survey estimates that , since 1900 , there have been an average of 18 major earthquakes ( magnitude 7.0 – 7.9 ) and one great earthquake ( magnitude 8.0 or greater ) per year , and that this average has been relatively stable .
 United States Geological Survey
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 United States Geological Survey