a mock chemical attack exercise, 模擬化學攻擊的演習

French firemen wearing chemical protective suits take part in a mock chemical attack exercise at the Geoffroy Guichard stadium in Saint-Etienne, France, April 4, 2016 in preparation of security measures for the UEFA 2016 European Championship. (REUTERS/Robert Pratta)
Photos of the day - April 4, 2016
https://www.yahoo.com/news/photos/photos-of-the-day-april-4-2016-1459784158-slideshow/photos-of-the-day-april-4-2016-photo-1459784581608.html