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-DOCSTART- ATTENTION : If you are awaiting rescue , do this to make yourself visible ! ! per @HCSOTexas . Please pass the word . # HoustonFlooding https://t.co/N4gwRLoI2y
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: exact location, area, road, river 
Text: {0} 
Answer:
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