A nurse holds a young girl who was vaccinated at the kickoff of a national measles prevention campaign in Liberia. Jason Beaubien/NPR hide caption

After completing training in 2013, Claire Kerstetter now works as a fluid technician on fracking jobs. Jeff Brady/NPR hide caption

The Sweet Briar College campus in western Virginia. Aaron Mahler/Sweet Briar College hide caption

Not exactly what that's for: Two tourists climb on a statue in Huayin, China, near Huashan, or Mount Hua, a famed tourist destination, in May 2013. ChinaFotoPress via Getty Images hide caption

Here's the band. Sarah Giffrow/The Slants hide caption

Russian military personnel march in Moscow's Red Square during a rehearsal Thursday for the Victory Day military parade that will take place Saturday to celebrate the 70th anniversary of the victory over Nazi Germany in World War II. Ivan Sekretarev/AP hide caption

Attorney General Loretta Lynch, seen here with Baltimore police Commissioner Anthony Batts, met Tuesday with the city's police officers, faith leaders and the family of Freddie Gray. Getty Images hide caption

Pastor Rodney Hudson sits on the steps of Ames Memorial United Methodist Church in West Baltimore, blocks away from the center of the protests and rioting that occurred last month. Hansi Lo Wang/NPR hide caption

U.S. Steel's Minntac taconite mine and plant looms over the city of Virginia. The company plans to lay off around 700 employees on June 1. Dan Kraker/MPR hide caption

Sir David Attenborough at the Beijing Museum of Natural History with fossil of Juramaia, as featured in the Smithsonian Channel series Rise of Animals: Triumph of the Vertebrates. Courtesy Smithsonian Channel hide caption