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 Psychological training and increased security that many schools instituted after the killing of 13 people in 1999 at Columbine High School in Colorado have given teachers and principals new tools and insights to spot potential trouble , the experts said . 
 Colorado, Columbine High School
Please list all entity pairs containing a certain relationship in the given options.Output format is "word1, word2; word3, word4". 
Option: nationality, country capital, place of death, children, location contains, place of birth, place lived, administrative division of country, country of administrative divisions, company, neighborhood of, company founders 
Text: {0} 
Answer:
 Colorado, Columbine High School