A string is used to ensure that the skirts of female members of the honour guard are in the same height from the ground as they prepare for a welcoming ceremony for Congo Republic President Denis Sassou Nguesso outside the Great Hall of the People in Beijing, China, July 5, 2016. (Photo by Jason Lee/Reuters)

A woman carrying a bundle on her head wait in line to cross the border into Colombia through the Simon Bolivar bridge in San Antonio del Tachira, Venezuela, Sunday, July 17, 2016. Tens of thousands of Venezuelans crossed the border into Colombia on Sunday to hunt for food and medicine that are in short supply at home. It's the second weekend in a row that Venezuela’s government has opened the long-closed border connecting Venezuela to Colombia. (Photo by Ariana Cubillos/AP Photo)

Revellers chat on Havana's Malecon seafront before performing at a carnival parade, Cuba, August 12, 2016. (Photo by Alexandre Meneghini/Reuters)

Praia du Forte, Bahia. “This was the lead picture for a National Geographic story on Bahia, because it was both mysterious as well as a “geography” picture showing where the slaves arrived from Nigeria. Beach pictures seem like they should be easy to take, but for me they are actually quite difficult. Too easy to fall into cliche. When I saw the kid coming on the horse, I quickly ran to see if I could make something with a woman in a bikini that was not a bikini shot”. (Photo by David Alan Harvey/The Guardian)

Pakistani youths cool off in a stream during hot weather on the outskirts of Islamabad on April 29, 2016. Pakistan's Meteorological Department has forecast hot and dry weather in most parts of the country with the highest temperatures recorded at 41 celsius in the southern Sindh province. (Photo by Aamir Qureshi/AFP Photo)

A demonstrator holds a rose and shouts slogans in front of a riot policeman during an unauthorized march called by secondary students to protest against government education reforms in Valparaiso, Chile, May 26, 2016. (Photo by Rodrigo Garrido/Reuters)

A group of Japanese schoolgirls marching in formation during a school visit to the third regiment to experience the soldier's way of life. (Photo by Fox Photos/Getty Images). Circa 1938

A girl bathes to cool off herself with water that is leaking from a broken pipe valve on a hot summer day on the outskirts of Ahmedabad, India, May 18, 2015. (Photo by Amit Dave/Reuters)