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)

Four hundred buyers from around the world join 260 diamond manufacturing and trading firms on International Diamond Week as some 1,500 people are expected to trade more than billion of polished diamonds this week in Ramat Gan, Israel on February 16, 2016. The Israel Diamond Exchange is considered the most secure in the world, covering an area of 100,000 square meters with 3,500 bourse members. (Photo by Nir Alon via ZUMA Wire)

People look at a tanker after it fell into a caved-in area on a road in Xi'an, Shaanxi province, July 27, 2013. No casualty was reported in the accident, according to local media. (Photo by Reuters/Stringer)

A Nepalese boy gets ready to perform a stick dance during a rally held to pay tribute to the victims of an earthquake, in Bhaktapur, Nepal, Wednesday, September 2, 2015. Two powerful earthquakes in April and May devastated the Himalayan nation killing more than 8,800 people. (Photo by Niranjan Shrestha/AP Photo)

A dancer lets a Russian tourist practice the traditional tannoura dance at a cafe in the Red Sea resort of Sharm el-Sheikh, Egypt November 10, 2015. The fallout from the crash of a Russian Metrojet passenger plane in Egypt's Sinai Peninsula could slash tourism income from Sharm al-Sheikh by half, the head of the region's travel agents' association said on Tuesday. Several airlines have suspended flights to the Red Sea resort since the Oct. 31 crash, which investigators and Western governments believe was likely to have been caused by a bomb. Thousands of Russian and British tourists have been flown home. (Photo by Asmaa Waguih/Reuters)

A person dressed as an astronaut walks past a man stopping traffic on a pedestrian crossing outside the Sydney Exhibition Centre September 13, 2014 where the science-fiction convention called “Oz Comic-Con” is currently being held. The two-day convention showcases “pop culture”, and includes appearances by actors from science-fiction movies and television shows. (Photo by David Gray/Reuters)

“El rio mas bonito del Mundo”, the most beautiful river of the world, the “River of five colors”, the “Rainbow River”, or even the “Escaped from Paradise”, are the shimmering appellations that Colombians give to Cano Cristales, a small stream located in the heart of the Macarena National Park, 150 km (93 miles) south of Bogota. Photo: A waterfall is seen at the end of the rainy season, in August, when the water level finally decreases, in the Cano Cristales RIver in the Sierra de la Macarena in Colombia. It has become covered with a bright pink endemic aquatic plant, Macarenia Clavigera. (Photo by Olivier Grunewald)

A model poses at Checkpoint Charlie, a historic place in the German capital to promote the fashion magazine “Sous” on June 12, 2012. (Photo by Maurizio Gambarini)