Tatiana Osorio, of Orlando, cries while giving blood at the OneBlood blood center near the mass shooting at a nightclub, June 13, 2016, in Orlando, Fla. Osorio lost three friends in the shooting. (Photo by David Goldman/AP Photo)

Two Czech Gripen fighter planes demonstrate a flight interception of a Belgian air force transport plane over the Czech Republic, as part of NATO drills on September 12, 2018. (Photo by Francois Lenoir/Reuters)

A fisherman throws a net for catching fish with his wife in Yanhu fisherman village near Yangzhou, Jiangsu province, China, 18 October 2018. (Photo by Aleksandar Plavevski/EPA/EFE)

The secretive indri (Indri indri) of Madagascar, the largest living lemur. It is also critically endangered and highly evolutionarily distinct with no close relatives, which makes its branch one of most precarious on the mammal evolutionary tree. In the likely event that the indri goes extinct, we will lose 19m years of unique evolutionary history from the mammal tree of life. (Photo by Pierre-Yves Babelon/Aarhus University)

PH Sport's driver Sebastian Loeb races against an airplane during a performance act at the Peru Dakar Rally in Lima, Peru on January 5, 2019. (Photo by Carlos Jasso/Reuters)

A visitor jumps for a photograph on the world's highest and longest glass-bottomed bridge above a valley in Zhangjiajie in China's Hunan Province on August 21, 2016. The bridge, which opened to the public on a trial basis on Saturday, spans 430 meters (1,410 feet) and rises about 300 meters (984 feet) above a valley in a scenic zone, making it the world's highest and longest glass-bottomed bridge according to Chinese state media. (Photo by Fred Dufour/AFP Photo)

A stray puppy walks along abandoned train tracks near the Chernobyl nuclear power plant on August 19, 2017 near Chornobyl, Ukraine. An estimated 900 stray dogs live in the exclusion zone, many of them likely the descendants of dogs left behind following the mass evacuation of residents in the aftermath of the 1986 nuclear disaster at Chernobyl. (Photo by Sean Gallup/Getty Images)

Carved pumpkins designed by US pumpkin artist Ray Villafane are pictured during a pumpkin exhibition in Ludwigsburg, southern Germany, on September 8, 2017. (Photo by Sebastian Gollnow/AFP Photo/DPA)