A panda bear sits on a logs in a zoo on January 15, 2015 in Hangzhou, China. (Photo by Feature China/Barcroft Media)

A pink elephant balloon, one of the entries in the Canadian Hot Air Balloon Championships, lands in a field in High River September 27, 2013. The event is a qualifier for the World Hot Air Balloon Championships in Sao Paulo in 2014. (Photo by Mike Sturk/Reuters)

In this handout from the Ministry of Defence, Royal Air Force VC10 and Tristar air-to-air refuelling aircraft support the first UK air combat mission in support of UN Resolution 1973 in flight on March 19, 2011. Col Muammar Gaddafi has vowed a “long war” against the “crusader aggression” after over 100 missiles were fired by the US and UK, during multi-national action aimed at enforcing a UN-mandated no-fly zone. (Photo by SAC Neil Chapman/MoD via Getty Images)

A pilot looks up from a U.S. F-22 Raptor fighter as it prepares to refuel in mid-air with a KC-135 refuelling plane over European airspace during a flight to Britain from Mihail Kogalniceanu air base in Romania April 25, 2016. (Photo by Toby Melville/Reuters)

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

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

A bus goes through a flooded street in Wuhan, Hubei province, China July 6, 2016. (Photo by Reuters/China Daily)

Girls rest on stairs at the China Digital Entertainment Expo and Conference (ChinaJoy) in Shanghai, China July 27, 2017. (Photo by Aly Song/Reuters)