A demonstrator catches fire after the gas tank of a police motorbike exploded during clashes in a protest against Venezuelan President Nicolas Maduro, in Caracas on May 3, 2017. Venezuela' s angry opposition rallied Wednesday vowing huge street protests against President Nicolas Maduro' s plan to rewrite the constitution and accusing him of dodging elections to cling to power despite deadly unrest. (Photo by Juan Barreto/AFP Photo)

An Indian nomadic Gujjar girl hangs on to a horse cart after collecting bricks from debris on the outskirts of Jammu, India, Tuesday, March 7, 2017. The Gujjar tribal communities are considered by some to be economically and socially backward and the lack of care by the state government has led to resentment amongst the community. The tribe moves to the plains from the hills to escape the cold winters. (Photo by Channi Anand/AP Photo)

A South China Tiger cub meets public at Guangzhou Zoo on June 22, 2017 in Guangzhou, Guangdong Province of China. Guangzhou Zoo boasts of the successful breeding of South China Tiger cub after 15 years. (Photo by VCG/VCG via Getty Images)

A herd of elephants cross a road that passes through the flooded Kaziranga National Park in the northeastern state of Assam, India, July 12, 2017. (Photo by Anuwar Hazarika/Reuters)

Supporters of Filipino boxer and Senatorial candidate Manny Pacquiao, wait for election souvenirs thrown by Pacquiao during election campaigning in Malabon Metro Manila in the Philippines May 6, 2016. Boxing star Manny Pacquiao pressed on with his campaign for a seat in the Philippine Senate despite a reported militant plot to kidnap him. (Photo by Erik De Castro/Reuters)

Veteran cholita wrestler Jennifer dos Caras, 45, holds a cement block over teen wrestler Lucero la Bonita in the ring in El Alto, Bolivia, Monday, January 21, 2019. Trainees of cholita wrestling are still a year away from their full professional debuts while competing in matches against established athletes. (Photo by Juan Karita/AP Photo)

Kyrgyz dancers perform in an event gathering bedouins and nomads from around the world as part of the annual King Abdulaziz Camel Festival in Rumah desert, northeast of the Saudi capital Riyadh, on March 19, 2019. (Photo by Fayez Nureldine/AFP Photo)

A vendor sleeps as his son waits for customers at their roadside vegetable shop in New Delhi, February 12, 2019. (Photo by Adnan Abidi/Reuters)