In this photo taken on Thursday, July 23, 2015 migrants enter a train to Serbia at the railway station in the southern Macedonian town of Gevgelija. The country has become a major transit route for thousands of Middle Eastern and African refugees and migrants who cross over from Greece and then continue into Serbia. (Photo by Boris Grdanoski/AP Photo)

Couples take part in a competition during a mass wedding of 64 doctoral student couples at Harbin Institute of Technology, a university in Harbin, Heilongjiang province, China, June 4, 2017. (Photo by Reuters/Stringer)

Smoke billows from a high-rise apartment building in west London Wednesday, June 14, 2017. A massive fire raced through the building early Wednesday, emergency officials said. (Photo by Rick Findler/PA Wire via AP Photo)

Convicted murderer Hector Alvarado Mazariegos, right, drops to the ground as he is hit by bullets of a Guatemala firing squad in the public cemetery at Mazatenango, June 28, 1975. His companion, Rocael Ortiz, met the same fate a few seconds later. Both were convicted of murder. (Photo by AP Photo/Anzueto)

Mae Zelinsky, left, and Betty O'Beda test ammunition on a .30 caliber rifle at a Remington Arms plant on April 30, 1943. Many women took over jobs that were left vacant when men went overseas to fight in World War II. (Photo by AP Photo)

France fan before the Russia 2018 World Cup Group C football match between Denmark and France at the Luzhniki Stadium in Moscow on June 26, 2018. (Photo by Axel Schmidt/Reuters)

Some people prepare to catch offerings thrown by Tengger tribe people into the crater of Bromo volcano to in Probolinggo, East Java province, on June 30, 2018, as part of Yadnya Kasada festival which falls on the 14th day of the Kasada month based on the traditional Hindu lunar calendar. (Photo by Juni Kriswanto/AFP Photo)

A grey seal basks under a rainbow on a beach on the Lincolnshire coast, England on November 21, 2017. (Photo by Sean Weekly/Caters News Agency)