A US Army M1A2 SEP tank participates in the Strong Europe Tank Challenge 2017 at the military training area in Grafenwoehr, Germany, 12 May 2017. Six North Atlantic Treaty Organization (NATO) nations and partner nations, Austria, France, Germany, Poland, Ukraine and the USA are taking part in this competing exercise. (Photo by Christian Bruna/EPA)

New Orleans police officers try to keep their heads down as they move in on a Black Panther headquarters during an exchange of gunfire in New Orleans on September 15, 1970. The shootout occurred as police moved in to make arrests on Tuesday morning following a series of incidents. (Photo by Jack Thornell/AP Photo)

An Indian nomadic shepherd from the western Rajasthan state guides his flock of sheep through an access road in Greater Noida, outskirts of New Delhi, India, Tuesday, December 5, 2017. Looking for suitable pasture lands for grazing, shepherds migrate their flocks over extensive areas in the same state or to neighboring states in India. (Photo by R.S. Iyer/AP Photo)

A worker cleans the statue of Yuri Gagarin, the first person who flew to space, ahead of Cosmonautics Day celebrated on April 12, in Moscow, Russia, Wednesday April 10, 2019. Cosmonautics Day marks when Soviet cosmonaut Yuri Gagarin became the first man to fly in space, in 1961, orbiting the earth once before making a safe landing. (Photo by Maxim Marmur/AP Photo)

Members of the U.S. Army's Golden Knights parachute team perform during the Bethpage Air Show as part of a Memorial Day event at Jones Beach on Long Island, New York, U.S., May 25, 2019. (Photo by Johnny Milano/Reuters)

People spend the summer at Qingdao seaside in Shandong, China on July 3, 2019. The maximum temperature of Qingdao beach was 26 degrees Celsius on that day, and all the 9 sea bathing places were open, attracting a large number of visitors to the seaside to enjoy the cool world. (Photo by Huang Jiexian/ZUMA Press)

Spectators in fancy dress during Day 7 of The Championships – Wimbledon 2019 at the All England Lawn Tennis and Croquet Club on July 8, 2019 in London, England. (Photo by Carl Recine/Reuters)

An Iran fan attends the Russia 2018 World Cup Group B football match between Morocco and Iran at the Saint Petersburg Stadium in Saint Petersburg on June 15, 2018. (Photo by Dylan Martinez/Reuters)