Second Ypres 1915: The Great gas Attack! Trailer 動画 YouTube https://www.youtube.com/watch?v=rk6_O_exW1Q Chlorine gas was used for the first time on April 22, 1915, in the Ypres Salient. Ypres 1915: The First Gas Attack September 21, 2014 Legion Magazine Without warning, a yellowish-green cloud began…