An Omani woman prepares for a traditional dance during a ceremony attended by Britain's Prince Charles and his wife, Camilla, Duchess of Cornwall in Muscat, Oman, Saturday, November 5, 2016. The royal couple have started a three-nation royal tour of the Gulf in Oman. (Photo by Kamran Jebreili/AP Photo)

A Hong Kong Vegetarian Society activists lies on a giant plate alongside oversized peas, carrots and cutlery during a protest rally in the tourist district of Tsim Sha Tsui, Hong Kong, China, 23 December 2015. The activists urged passers-by to extend the holiday spirit to animals and to give thoughts to the cruelty inflicted on animals in meat productions. (Photo by Jerome Favre/EPA)

Bjorn, aged 5, smiles as he poses with a Owl butterfly during an event to launch the Sensational Butterflies exhibition at the Natural History Museum in London, Britain March 23, 2016. The exhibition opens to the public on March 24 and runs until September 11. (Photo by Dylan Martinez/Reuters)

Alluvial Fan, China. A vast alluvial fan blossoms across the desolate landscape between the Kunlun and Altun mountain ranges that form the southern border of the Taklimakan Desert in China’s XinJiang Province. Image taken by the ASTER instrument on NASA’s Terra satellite on May 2nd, 2002. (Photo by NASA/GSFC/USGS EROS Data Center)

A Ukrainian serviceman fires a 2S7 Pion self-propelled gun during military exercises near the village of Divychky in Kiev region, Ukraine, October 21, 2016. (Photo by Valentyn Ogirenko/Reuters)

A woman jumps on a giant fried egg art installation as part of “Hecho en Casa” (Made at home) urban artwork festival in downtown Santiago, Chile, November 8, 2016. (Photo by Pablo Sanhueza/Reuters)

Israeli soldiers cry during a state memorial ceremony marking two years since the 2014 Gaza war “Operation Protective Edge” at Mount Herzl military cemetery in in Jerusalem, Israel, 26 July 2016. More than 2.000 people were killed in the conflicts between Israel and Palestine. (Photo by Abir Sultan/EPA)

Engine driver Josef Kowatsch (top L) steers a train through the NEAT Gotthard Base Tunnel during a media visit near the town of Erstfeld August 24, 2015. Crossing the Alps, the world's longest train tunnel should become operational at the end of 2016, consisting of two parallel single track tunnels, each of a length of 57 km (35 miles). (Photo by Arnd Wiegmann/Reuters)