Students exercise in body training at Bishan Vocational Education Center in Chongqing, southwest China, January 13, 2016. These students were trained to be stewardesses of the high-speed train. (Photo by Xie Jie/Xinhua)

An election poster calling for the legalisation of marijuana and featuring internet meme “Grumpy Cat” hangs outside the Pirate Party's campaign headquarters in Berlin on August 16, 2013. The Pirates, who to everyone's surprise were elected into Berlin's regional parliament in September 2011, are trying to capitalise on their recent electoral gains in upcoming parliamentary elections, running on a platform of transparency in government. Germany goes to the polls on September 22, 2013. Placard reads: “Hurry up, my dope is everything”. (Photo by John Macdougall/AFP Photo)

In this photo posted on Twitter, Sunday, May 3, 2015, and provided by NASA, Italian astronaut Samantha Cristoforetti sips espresso from a cup designed for use in zero-gravity, on the International Space Station. Cristoforetti, the first Italian woman in space, fired up the first espresso machine in space, which uses small capsules, or pods, of espresso coffee. (Photo by AP Photo/NASA)

In this photo taken Saturday, January 24, 2015, a child makes a face while having her photo taken with the snow covered slopes of the Nanshan ski resort behind her in Beijing. As Beijing makes a final push in its bid for the 2022 Winter Olympics, Chinese President Xi Jinping says winning the bid will encourage over 300 million Chinese to take up winter sports by 2022, according to state-run Xinhua News agency. (Photo by Ng Han Guan/AP Photo)

Kristina Elekes, 23, races on her ski during the Bikini Race contest held at Arena Platos Paltinis winter resort, near Sibiu city, 275 Km north from Bucharest, Romania, 06 March 2016. Bikini Race is a timed show on the slopes, at the fourth edition, for women dressed only in swimmsuits and some winter accessories. (Photo by Mihaela Bobar/EPA)

Riot police runs as a woman falls down during a May Day rally in the Kreuzberg district of Berlin, Germany, 01 May 2016. (Photo by Kay Nietfeld/EPA)

Poland's Dawid Kubacki soars through the air during the men's FIS Ski Jumping World Cup competition in Engelberg, central Switzerland, on December 20, 2014. (Photo by Fabrice Coffrini/AFP Photo)

People sit near a fully loaded in Madama near the border with Lybia on January 1, 2015. French Defence Minister Jean-Yves Le Drian paid a surprise visit to northern Niger on January 1, to visit a base being built to combat the growing flow of weapons and jihadists from neighbouring Libya. Le Drian travelled from Chad to Madama, a desert outpost about 100 kilometres from Libya, where he saw in the New Year with troops at a French base. Madama is situated on the route used by jihadists and arms smugglers in southern Libya to reach northern Mali and Niger. (Photo by Dominique Faget/AFP Photo)