Nuns react at the arrival of Pope Francis at the St. Mary's school to attend a meeting of clergy and religious in Nairobi, Kenya, 26 November 2015. Pope Francis is on a six days visit that will take him to Kenya, Uganda and the Repulic of Central Africa from 25 to 30 November. (Photo by Daniel Dal Zennaro/EPA)

A model has a wig prepared backstage before The Blonds Spring/Summer 2017 collection during New York Fashion Week in the Manhattan borough of New York, U.S., September 11, 2016. (Photo by Lucas Jackson/Reuters)

A model poses at the Hashe presentation during Fashion Forward Spring/Summer 2017 at the Dubai Design District on October 21, 2016 in Dubai, United Arab Emirates. (Photo by Cedric Ribeiro/Getty Images)

This picture taken on October 20, 2016 shows students practising wushu at the Tagou martial arts school in Dengfeng. China is investing hugely in football training and has vowed to have 50 million school- age players by 2020, as the ruling Communist party eyes “football superpower” status by 2050. (Photo by Nicolas Asfouri/AFP Photo)

A man rides a motorcycle along a street in the snow in Altay, Xinjiang Uighur Autonomous region, February 9, 2016. (Photo by Reuters/Stringer)

A fighter belonging to Jaish al-Islam (Islam Army) runs to take cover near the frontline on March 14, 2016 in the neighbourhood of Jobar, on the eastern outskirts of the capital Damascus. (Photo by Amer Almohibany/AFP Photo)

A woman and a child make a bonfire at a makeshift camp for migrants and refugees at the Greek-Macedonian border near the village of Idomeni, Greece, April 1, 2016. (Photo by Marko Djurica/Reuters)

An animal rights activist, wrapped in packaging labelled “carne humana” (human meat), participates in a protest against meat consumption to promote vegetarianism in central Barcelona, in Spain, May 22, 2016. (Photo by Albert Gea/Reuters)