In this Wednesday, January 23, 2019, an anti-government protester covers her face with a Venezuelan flag, and uses toothpaste around her eyes to help lessen the effect of tear gas, during clashes with security forces after a rally demanding the resignation of President Nicolas Maduro in Caracas, Venezuela. The head of Venezuela's opposition-run congress declared himself interim president at the rally, until new elections can be called. (Photo by Fernando Llano/AP Photo)

Protesters run for cover after riot police fired tear gas towards the bridge they were climbing down to the road below, to escape from Hong Kong Polytechnic University campus and from police, in Hung Hom district in Hong Kong on November 18, 2019. Dozens of Hong Kong protesters escaped a besieged university campus on November 18 by lowering themselves on a rope from a footbridge to a highway, AFP video showed. Once on the road they were seen being picked up by waiting motorcyclists. (Photo by Anthony Wallace/AFP Photo)

In this April 20, 2017 photo, a woman is aided by fellow demonstrators after falling, overcome by tear gas, during anti-government protests in Caracas, Venezuela. Tens of thousands of protesters asking for the resignation of President Nicolas Maduro flooded the streets again, one day after three people were killed and hundreds arrested in the biggest anti-government demonstrations in years. (Photo by Ariana Cubillos/AP Photo)

A student aims a stick of wood at Bolivarian National Police officers during clashes outside the Central University in Caracas, Venezuela, Thursday, June 9, 2016. Students had planned to march from Venezuela's top university to elections headquarters, but hundreds of police in riot gear blocked the way. Students covered their faces with Venezuelan flags and threw bottles, stones and sticks while police lobbed tear gas. (Photo by Fernando Llano/AP Photo)

Secondary school students perform a barefoot “pilgrimage of suffering” to support the Occupy Central civil disobedience movement at the Admiralty protest site in Hong Kong November 30, 2014. It has been two months since police first fired tear gas to disperse demonstrators from the main protest site in the Admiralty district next to government offices in the heart of the Asian financial centre. (Photo by Bobby Yip/Reuters)

The R.C. Bush Pilots club was started in 1981, for those who enjoy flying radio control (RC) model planes. It’s one of the largest clubs in Florida, and calls Phil Wherry Field in West Palm Beach home. Photo: Professional pilot and remote control plane enthusiast Bob Rembert prepares to start the propeller of a 1/4 scale Edge 540 remote control, gas powered plane. (Photo by Bill Ingram/The Palm Beach Post)

A demonstrator is detained by police officers during a protest in Hong Kong, China on August 31, 2019. Hong Kong police fired tear gas and water cannons and pro-democracy protesters threw petrol bombs in the latest in a series of chaotic clashes that have plunged the Chinese-ruled city into its worst political crisis in decades. (Photo by Kai Pfaffenbach/Reuters)

In this September 19, 2019 file photo, an aircraft passes the rising sun during take off at the international airport in Frankfurt, Germany. Germany’s top court has ruled that the government has to set clear goals for reducing greenhouse gas emissions after 2030, arguing that current legislation doesn’t go far enough in curbing climate change. (Photo by Michael Probst/AP Photo/File)