Migrants react after boarding the Migrant Offshore Aid Station (MOAS) ship MV Phoenix some 20 miles (32 kilometres) off the coast of Libya, August 3, 2015. Some 118 migrants were rescued from a rubber dinghy off Libya on Monday morning. The Phoenix, manned by personnel from international non-governmental organisations Medecins san Frontiere (MSF) and MOAS, is the first privately funded vessel to operate in the Mediterranean. (Photo by Darrin Zammit Lupi/Reuters)

In this photo taken on July 19, 2014, a man looks at an excavation as an A.R.M.H., Association for the Recovery of Historical Memory, volunteer digs on the search for the body of Perfecto de Dios, in a hidden grave in Chaherrero, Spain. Across Spain, volunteer teams of archeologists, anthropologists and forensic scientists head out every year on expeditions to dig for suspected mass graves – a legacy of Spain's fascist past during the time of General Francisco Franco. (Photo by Daniel Ochoa de Olza/AP Photo)

Lindsay Mann (L) and Anabella Mowbray kiss as they take photos of themselves laying in the confetti on 7th Avenue in Times Square on New Year's Eve in New York January 1, 2015. (Photo by Carlo Allegri/Reuters)

Alfred the frog looks almost as scary as the pumpkin he is perched on at London Zoo 26 October 2011. Keepers at the zoo have joined in the Halloween tradition by supplying pumpkin lunches to some of their animals, including the giant waxy monkey frog. However Alfred is not quite the giant figure his species name suggests – he actually measures up at around 4 inches (10 centimeters). (Photo by EPA/Zoological Society of London)

Performers dressed like Stormtroopers dance during “The Empire Strips Back: A Star Wars Burlesque Parody” in Los Angeles, California, U.S., June 1, 2018. (Photo by Mario Anzuoni/Reuters)

In this Thursday, June 14, 2018, file photo, students wear virtual reality goggles during a science class at Pyongyang Teachers' University, a teacher training college, in Pyongyang, North Korea. (Photo by Dita Alangkara/AP Photo)

Tightrope walker Tatian-Mosio Bongonga hangs from a tightrope as she pauses while scaling the Monmartre hill towards the Sacre Coeur Basilica (not pictured) in Paris, France, July 20, 2018. (Photo by Philippe Wojazer/Reuters)

A police officer pepper sprays a protester as another protester stands in front of the race director's car during a farmers' protest who attempted to block the stage' s route, during the 16 th stage of the 105 th edition of the Tour de France cycling race, between Carcassonne and Bagneres- de- Luchon, southwestern France, on July 24, 2018. The race was halted for several minutes on July 24 after tear gas was used as protesting farmers attempted to block the route. (Photo by Stephane Mahe/Reuters)