“The Challenge!” Young boy relishes in a game of tug of war before school. Photo location: Lake Titicaca, Peru. (Photo and caption by Paul Heyman/National Geographic Photo Contest)

Belgium. Rosalie, 9, goes to school in Brussels. “At my school we have separate toilets for girls and boys on every floor. My classroom is on the 3rd floor. We have 22 toilets, which are shared between 230 pupils and 20 adults. The teachers at school let us go to the toilet whenever we need to”. (Photo by Tim Dirven/WSUP/Panos)

Contestants of a tourism beauty pageant balance eggs on their collarbones as they cruise along the Yellow River in Jiyuan, Henan province, China, June 22, 2015. The contestants believe that if they are slim enough, their collarbones will allow them to balance the eggs securely on their bodies. (Photo by Reuters/Stringer)

Jockeys spur buffalos during the Makepung buffalo races at Jembrana in Bali, Indonesia on October 23, 2016. Makepung is a tradition for farmers to celebrate a bumper harvest in Bali. (Photo by Kadek Raharja/Xinhua/Barcroft Images)

Indian folk dancers display ornaments during a break while participating in the first night of Navratri in Gandhinagar, some 30 km from Ahmedabad, on October 13, 2015. Navratri festivities, or Dance Festival of Nine Nights, takes place between October 13-21. (Photo by Sam Panthaky/AFP Photo)

A model stands next to a BMW X6 AC Schnitzer car at Auto China 2012 in Beijing in this April 24, 2012 file photo. Amid the razzmatazz, music and crowds at the Shanghai autoshow on Monday, hundreds of attractive young women, and men, mingled among the stands and company booths, introducing the newest sedans and handing out pamphlets. For years, models have been a staple at China's big autoshows – as much of a draw as the latest car models themselves. 2015 is different – the organisers have banned models from the Shanghai show. (Photo by Jason Lee/Reuters)

Some Iraqi candidates for Miss Iraq beauty contest pose in front of the Ishtar Gate at the ancient archaeological site of Babylon, outside the modern city of Hilla, south of the capital Baghdad on December 17, 2015. The beauty contest, which is the first one in more than 40 years, aims to boost tourism in the city and will take place on December 19, 2015. (Photo by Ahmad Al-Rubaye/AFP Photo)

Tourists walk behind a faded sign warning of tsunami hazard in Khao Lak, Phang Nga province December 15, 2014. Ahead of the anniversary of the 2004 tsunami, experts and officials say key weaknesses remain across the region in the system designed to warn people of the next disaster, and get them to safety. Thailand prepares to mark the tenth anniversary of the 2004 tsunami, the deadliest on the record, that killed at least 226,000 people in 13 Asian and African countries. (Photo by Damir Sagolj/Reuters)