Tour guides wearing traditional Chinese dress practice smiling by biting chopsticks at Qingming Grand-River Park in Kaifeng, central China's Henan Province on March 2, 2017, aiming to provide better service for visitors. (Photo by IPA Asia via ZUMA Wire)

A member of the Tinstix of Dynamite aerobatics team flies in front of a wall of fire during the Australian International Airshow in Melbourne on March 5, 2017. The annual event sees 180,000 visitors over the 3-day public event held at the Avalon Airfield some 80kms south-west of Melbourne. (Photo by Mal Fairclough/AFP Photo)

US freestyler, gold medalist Mcrae Williams competes during the men' s SlopeStyle (SS) finals at the FIS Snowboard and Freestyle Ski World Championships 2017 in Sierra Nevada on March 19, 2017. (Photo by Albert Gea/Reuters)

A Romanian female soldier adjusts her helmet before taking part in weapons training with US Marines female counterparts at the Capu Midia Surface to Air Firing Range, on the Black Sea coast in Romania, Monday, March 20, 2017. About 1,200 US and Romanian troops take part in the Spring Storm 17 exercise, meant to simulate defense of the Romanian Black Sea coastline and urban areas. (Photo by Vadim Ghirda/AP Photo)

Brides-to-be participate in the “Running of the Brides” race in a park in Bangkok, Thailand March 25, 2017. (Photo by Athit Perawongmetha/Reuters)

A goat begs for food as people have a meal and beer at the Beichelstein-Alpe outdoor restaurant near Seeg, southern Germany, on March 27, 2017. (Photo by Karl-Josef Hildenbrand/AFP Photo/DPA)

Demonstrators protest during a rally against Venezuelan President Nicolas Maduro, in Caracas on April 19, 2017. Venezuela braced for rival demonstrations Wednesday for and against President Nicolas Maduro, whose push to tighten his grip on power has triggered waves of deadly unrest that have escalated the country' s political and economic crisis. (Photo by Juan Barreto/AFP Photo)

Cardboard cut outs of the faces of three candidates for the Republican nomination for the 2016 US Presidential election (L-R) Ted Cruz, Donald Trump and Marco Rubio, are seen set up on urinals in a pub in London on March 1, 2016 as part of an informal poll for customers to log which they dislike the most. Part of the satirical television show The Last Leg, customers at the pub are able to choose which urinal to use and then log their poll on a list on the wall afterwards. (Photo by Justin Tallis/AFP Photo)