A competitor walks on tightrope during a performance in Taizhou, Zhejiang Province, China, May 7, 2016. (Photo by Reuters/China Daily)

Kurdish guard women from the civilian protection unit which supports the Democratic Forces of Syria, cheer near the Syrian town of al Houl in Hasaka province, after the Democratic Forces of Syria took control of the area, November 14, 2015. A U.S.-backed Syrian rebel alliance on Friday captured the town of al Houl in Hasaka province, which had been held by Islamic State militants, a spokesman for the Kurdish fighters, part of the grouping, said. It was the first significant advance against IS by the Democratic Forces of Syria, which was formed last month. (Photo by Rodi Said/Reuters)

A man rides his loaded tricycle next to three schoolgirls in Shanghai on December 11, 2015. (Photo by Johannes Eisele/AFP Photo)

Paramilitary policemen take part in a training in Chaohu, Anhui province, China December 28, 2015. (Photo by Reuters/China Daily)

National police transport an anti-government protester detainee during a protest against Nicolas Maduro's government in Caracas March 13, 2014. Venezuela's state prosecutor said on Thursday the death toll from a month of violent protests had risen to 28, after the nation's top court ordered opposition mayors to dismantle barricades set up by street protesters. State prosecutor Luisa Ortega Diaz, speaking on the sidelines of the U.N. Human Rights Council in Geneva, also said 1,293 detainees had been released and 104 remained in custody accused of serious crimes during the anti-government demonstrations. (Photo by Carlos Garcia Rawlins/Reuters)

Armed man stand at entrance of the naval headquarters in Sevastopol, March 19, 2014. Around a dozen Ukrainian servicemen, unarmed and in civilian clothes, walked out of the Ukrainian naval headquarters in the Crimean port of Sevastopol on Wednesday after it was taken over by pro-Russian forces, a Reuters witness said. (Photo by Baz Ratner/Reuters)

German shoemaker Georg Wessels (R) presents shoes to Win Zaw Oo, who according to his medical team, at 2.3 metres (7.5 ft), is Myanmar's tallest man, in Yangon March 26, 2014. (Photo by Reuters/Minzayar)

Members of the U.S. Army 173rd Airborne Brigade stand at attention as a Ukrainian folk dance group performs at the opening ceremony of the “Rapid Trident” NATO military exercises on September 15, 2014 near Yavorov, Ukraine. The two-week exercises include participating units from a variety of NATO and NATO-associate countries as well as Ukrainian troops. Meanwhile fighting between pro-Russian separatists and Ukrainian armed foces has flared again in eastern Ukraine in a battle for the control of Donetsk airport despite the tenuous ceasefire. (Photo by Sean Gallup/Getty Images)