A riot policeman watches as a police vehicle burns in Braamfontein, Johannesburg, South Africa, Tuesday, October 25, 2016. Rioters in South Africa set a police vehicle on fire Tuesday and stoned vehicles near a Johannesburg university that has been the scene of sometimes violent protests by students demanding free education. The violence broke out in streets near the University of the Witwatersrand at around the same time that student protesters met and marched off the campus, South African media reported. (Photo by Yeshiel Panchia/AP Photo)

A woman spends her time outdoors to observe the ancient festival of Sizdeh Bedar, an annual public picnic day on the 13th day of the Iranian new year, at the Tochal mountainous area northern Tehran, Iran, Sunday, April, 2, 2017. Sizdeh Bedar, which comes from the Farsi words for “thirteen” and “day out”, is a legacy from Iran's pre-Islamic past that hard-liners in the Islamic Republic never managed to erase from calendars. (Photo by Ebrahim Noroozi/AP Photo)

An inmate (L) tends to a fellow prisoner while performing ear candling during an alternative therapy session as part of the ACUDA programme, at a complex of ten prisons in Porto Velho, Rondonia State, Brazil, August 27, 2015. Ear candling, which involves inserting a hollow cone-shaped device into the ear canal and lighting the exposed end, is believed by practitioners to draw out earwax. According to ACUDA the therapy is beneficial for the inmates' emotional health. (Photo by Nacho Doce/Reuters)

One of the two wooden rafts of the Kon-Tiki II expedition is prepared at the port of Callao prior to the departure to Pascua island in Chile, in Callao, Peru, October 30, 2015. Fourteen men from various parts of the world set out on rafts to commemorate the Norwegian navigator Thor Heyerdahl expedition 68 years ago. The original raft crossed the Pacific Ocean from South America to the Polynesian Islands. This rafts are a replica of ships used 6,000 years ago, but will be equipped with solar panel. (Photo by Mariana Bazo/Reuters)

Ultra Orthodox Jews look at the body of an alleged Palestinian assailant in Jerusalem Saturday, December 26, 2015. According to a police spokeswoman, policemen approached a man who drew their suspicions just outside the Old City for following a pair of Jewish worshippers. Then he pulled out a knife and tried to stab one of them, officers opened fire and killed the assailant. (Photo by Mahmoud Illean/AP Photo)

Afghan girl athletes perform Wushu on the top of a hill in Kabul, capital of Afghanistan, January 18, 2017. In the conservative Afghan society where people especially in the countryside deeply believe in the old traditions and don't allow their girls and female members of the family to go out of home, exercising sport in open is extremely risky, but a group of girls are broken the taboo and exercising Wushu on a hilltop where the temperature is minus 2 Celsius degrees. (Photo by Rahmat Alizadah/Xinhua/Barcroft Images)

This huge male orangutan is having a right old laugh as he squints his eyes and shows his huge teeth. The orangutan, called Bimbo, was relaxing on a platform around 5m high in his enclosure when he broke out into a laugh. But his happy smile soon disappeared when another orangutan came over to see what was going on. Bimbo – the only male in the group of five apes at Leipzig Zoo, in Germany - appears to be laughing in much the same way as a human would. (Photo by Martina Radtke/Solent News)

A woman attends a boxing class at Princess Women's Boxing Club in Shanghai December 3, 2014. Women have boxed as long as the sport has existed but for years they were relegated out of national and international competitions in many countries around the world. Female boxers entered the ring in an exhibition match at the 1904 Olympic Games, but it was more than a century later when they were given the green light to make their Olympic debut in London in 2012. (Photo by Carlos Barria/Reuters)