National Guardsmen are put through riot training in Boston's Commonwealth Armory on Friday, October 18, 1974. Massachusetts Gov. Francis W. Sargent called up the guard to quell school violence, but the city has been relatively calm and the guard has remained in the armories. (Photo by JWG/AP Photo)

Japanese hairdresser Megumi Takeichi cuts patterns into the hair of a camel ahead of the Bikaner Camel Festival in Bikaner in the western Indian state of Rajasthan on January 10, 2019. (Photo by Dinesh Gupta/AFP Photo)

A partially burned American flag lies on the street near the spot where Michael Brown was killed before an event to mark the one year anniversary of his killing in Ferguson, Missouri August 9, 2015. (Photo by Rick Wilking/Reuters)

A woman promotes a go-go dance bar in Pattaya, Thailand March 25, 2017. With mascots dressed as smiling fish and a police rock band, Thai authorities launched a “Happy Zone” at the weekend to improve the image of a city notorious for sеx tourism. Stung by foreign headlines portraying the seaside resort of Pattaya as “Sin City” and “The World’s Sеx Capital”, Thailand’s junta has begun a new effort to re-brand it. Businesses in the Happy Zone are asked to make the area feel safer, there are increased security patrols, police launched a mobile phone app for visitors to summon them if an emergency occurs. (Photo by Jorge Silva/Reuters)

A pigeon rests on a wild iguana in a tree inside Seminario Park in Guayaquil, Ecuador, Thursday, April 3, 2014. Pigeons coexist with the wild iguanas at this park in the middle of the city surrounded by savannah. (Photo by Dolores Ochoa/AP Photo)

An artist shows her hands after working on a wall as part of a campaign to call for coexistence and the renouncement of violence through the painting of walls in Sanaa, Yemen March 15, 2015. (Photo by Mohamed al-Sayaghi/Reuters)

Supporters celebrate as they watch official results from the Union Election Commission on an LED screen in front of the National League for Democracy Party (NLD) head office in Yangon, November 9, 2015. Myanmar's ruling party conceded defeat in the country's general election on Monday, as the opposition led by democracy figurehead Aung San Suu Kyi appeared on course for a landslide victory that would ensure it can form the next government. "We lost," Union Solidarity and Development Party (USDP) acting chairman Htay Oo told Reuters in an interview a day after the Southeast Asian country's first free nationwide election in a quarter of a century. (Photo by Soe Zeya Tun/Reuters)

Lara Stone at Mark's Club on October 27, 2016 in London, England. (Photo by Mark Milan/GC Images)