Five year old George holds an orange to feed the Owl butterflies at the Natural History Museum in London, Thursday, March 30, 2017. Hundreds of tropical butterflies were released to launch the Natural History Museum's Sensational Butterflies exhibition, starting for the public on March 31, 2017. (Photo by Frank Augstein/AP Photo)

Aerobatic aircrafts fly during a performance at the Airshow Zhengzhou 2017 in Zhengzhou, capital of central China's Henan Province on April 27, 2017. The 5-day air show kicked off in Zhengzhou on Thursday, aiming to build a general aviation gathering center for business and communications. (Photo by Li An/Xinhua via ZUMA Wire)

A woman tries a swing in front of a screen featuring New York scenes during the new Air France Exhibition called “Air France, France is in the Air” in New York June 25, 2014. (Photo by Timothy A. Clary/AFP Photo)

A portrait of French WWI soldier Edouard Marius Ivaldi is displayed on a tablet, in this illustration picture, alongside his battlefield grave memorial, a wooden cross with a battlefield helmet in Champagne, eastern France, November 3, 2015. (Photo by Charles Platiau/Reuters)

A mechanical horse-dragon made of wood and steel is presented to the public in Nantes, western France on August 26, 2014. This horse-dragon, created by the French artist Francois Delaroziere of “Les Machines de l'île” (The Machines of the Isle), is the hero of the show "Long Ma" which will be presented in Beijing on October 17, 2014 as part of the fiftieth anniversary of the relationship between France and China. (Photo by Jean-Sebastien Evrard/AFP Photo)

Brett Gardner #11of the New York Yankees dives into second base on the back end of an attempted double during the first inning in a MLB baseball game at Yankee Stadium on September 3, 2014 in the Bronx borough of New York City. Gardner was tagged out on the play. (Photo by Rich Schultz/Getty Images)

Participants climb over a wall at the “Tough Mudder” endurance event series in Arnsberg September 6, 2014. Competitors who took part in the endurance event saw themselves having to overcome various military style obstacles. (Photo by Ina Fassbender/Reuters)

Liu Chunxia, a supporter of Xu Zhiyong, one of China's most prominent rights advocates, is detained by policemen while she gathers with other supporters nearby a court where Xu's trial is being held in Beijing January 22, 2014. When dozens of activists unfurled banners across the country last March and April calling for officials to disclose their assets, they did so at the urging of one of China's most prominent rights advocates, Xu Zhiyong. Xu, 40, stands trial on Wednesday on a charge of “gathering a crowd to disturb public order” punishable by up to five years in prison. His case will almost certainly spark fresh criticism from Western governments over Beijing's crackdown on dissent. (Photo by Kim Kyung-Hoon/Reuters)