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Americans sought to bring calm to Mosul , where U . S . troops killed 17 people in clashes earlier in the week .
 Mosul , where U . S . troops killed 17 people in clashes earlier in the week, where, U . S, Americans, U . S . troops, 17 people
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: organization, person, geographical social political, vehicle, location, weapon, facility 
Text: {0} 
Answer:
 Mosul , where U . S . troops killed 17 people in clashes earlier in the week, where, U . S, Americans, U . S . troops, 17 people