For the head of the FBI's counterterrorist division, Michael Steinbach, the unknown worries him the most.
원문출처 : http://edition.cnn.com/2015/02/03/politics/fbi-isis-counterterrorism-michael-steinbach/index.html?eref=edition
원문출처 : http://edition.cnn.com/2015/02/03/politics/fbi-isis-counterterrorism-michael-steinbach/index.html?eref=edition