Behind the walls at Emerson High School in Oklahoma City, construction workers found old chalkboards with drawings and class lessons, written almost a century ago and in remarkable condition.
Three test subjects enter a gas chamber, which will fill with mustard gas, as part of the military's secret chemical warfare testing in March 1945.
Courtesy of Edgewood Arsenal
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Bill Pentak of Panda Power Funds (left), Plant Manager John Martin (center) and Construction Manager Rob Risher (right) stand in front of the construction site for the new Panda Liberty gas power plant in Towanda, Penn. The plant, expected to come online in early 2016, was deliberately sited on top of the Marcellus Shale to take advantage of the cheap, abundant gas.
Marie Cusick/WITF
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Sun Jianguo (left), from the Chinese People's Liberation Army Navy, chats with U.S. Secretary of Defense Ashton Carter in May during the ministerial luncheon at the 14th Asia Security Summit in Singapore. Each country has grown increasingly wary of the other's actions and interests in the South China Sea.
Roslan Rahman/AFP/Getty Images
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