A Beijing Opera performer dances for a show by designer Hao Weimin at China Fashion Week, China, October 28, 2019. (Photo by Jason Lee/Reuters)

French aircrafts of the Patrouille de France spray colored smoke during a performance on the opening day of the Dubai Airshow in Dubai, United Arab Emirates, Sunday, November 17, 2019. (Photo by Kamran Jebreili/AP Photo)

Chinese butchers catch a pig to slaughter on January 31, 2005 in Jinzhai County, Anhui Province, China. (Photo by Cancan Chu/GettyImages)

Passengers wait for a train to depart from the Hankou Railway Station in Wuhan, central China's Hubei province, Friday January 13, 2017. Officials expect that Chinese travelers will make almost 3 billion trips during the holiday travel rush that starts runs through Feb. 21. These trips include intercity flights, trains and local bus rides to villages for China's 1.4 billion people. (Photo by Chinatopix via AP Photo)

Steam emerges from a cooling tower of the nuclear power plant Leibstadt near Leibstadt, Switzerland, November 18, 2014. (Photo by Arnd Wiegmann/Reuters)

People and sea-gulls bathe in the sea as the sun goes up with red colors in Stralsund close to the baltic sea island of Rügen, on early November 23, 2016. (Photo by Stefan Sauer/AFP Photo/DPA)

A Syrian Democratic Forces (SDF) female fighter adjusts a mortar in northern Deir al-Zor province ahead of an offensive against Islamic State militants, Syria February 21, 2017. (Photo by Rodi Said/Reuters)

Masked Guggen music bands parade through the streets on the occasion of the beginning of the Fasnacht Carnival of Lucerne, Switzerland, early 23 February 2017. (Photo by Urs Flueeler/EPA)