UN Secretary-General Ban Ki-moon address a ceremony celebrating the 15th anniversary of Preparatory Commission of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) in Vienna, capital of Austria, Feb. 17, 2012. <Photo: Xinhua/Xu Liang>
UN Secretary-General Ban Ki-moon address a ceremony celebrating the 15th anniversary of Preparatory Commission of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) in Vienna, capital of Austria, Feb. 17, 2012. <Photo: Xinhua/Xu Liang>
