Participants climb over a wall at the “Tough Mudder” endurance event series in Arnsberg September 6, 2014. Competitors who took part in the endurance event saw themselves having to overcome various military style obstacles. (Photo by Ina Fassbender/Reuters)

A hot air balloon flies close to the ground in the Jezreel Valley in northern Israel during an international hot air balloon festival October 14, 2014. (Photo by Nir Elias/Reuters)

Ecuadorian indigenous people celebrate the festival of the moon or Kulla Raymi, in Quito, Ecuador, 21 September 2021. A circle on the ground made up of fruits and inside the Andean symbol of the chacana, multinational geometric flags and a cross that symbolizes the four cardinal points, were the setting in which the festival of the moon, the Kulla, was commemorated this Tuesday. Raymi, on a hill in Quito. It is one of the four most significant festivities of the Andean agroecological calendar, which commemorates the beginning of life and exalts women as the maximum representation of fertility. (Photo by Jose Jacome/EPA/EFE)

Gun enthusiasts look over Smith & Wesson pistols at the NRA Annual Meetings & Exhibits on May 21, 2016 in Louisville, Kentucky. About 80,000 visitors are expected to attend the three-day event. (Photo by Scott Olson/Getty Images)

A zoo performer smiles as he puts his head between the jaws of a crocodile during a performance for tourists at the Sriracha Tiger Zoo, in Chonburi province, east of Bangkok,Thailand, June 7, 2016. (Photo by Chaiwat Subprasom/Reuters)

Kyaiktiyo, Burma, 1978. The Golden Rock at Shwe Pyi Daw (the Golden Country), the Buddhist holy place. Hiroji Kubota writes: “I was desperate to keep a distance from America for a while; luckily, I found Burma and its gentle and compassionate people. In the spring of 1978, on the top of the hill where I took this photo, I had two Leica bodies: the one with Tri-X and the other with Kodachrome 64. Soon after, I realised that the colour one looked very colourful and was more powerful. That was my decisive moment, to become a colour photographer”. (Photo by Hiroji Kubota/Magnum Photos)

A picture made available on 14 July 2016 shows Greyhound dogs racing at the Wentworth Park Stadium in Sydney, New South Wales (NSW), Australia, 13 July 2016. Greyhound racing has returned to Sydney's Wentworth Park and other NSW tracks for the first time since the state government announced plans to ban it. NSW Premier Mike Baird announced last week plans to shut down the sport in NSW following a Special Commission of Inquiry report that found “chilling” evidence of systemic animal cruelty within the industry. (Photo by David Moir/EPA)

Republican Presidential Candidate Donald Trump kisses his wife Melania Trump as he introduces her during first day of the Republican National Convention in Cleveland, Monday, July 18, 2016. (Photo by Matt Rourke/AP Photo)