Pope Francis greets the crowd from his popemobile in downtown Rio de Janeiro. Pope Francis touched down in Rio de Janeiro on Monday, starting his first foreign trip as pontiff and a weeklong series of events expected to attract more than a million people to a gathering of young faithful in Brazil, home to the world's largest Roman Catholic population. (Photo by Ueslei Marcelino/Reuters)

Karis, a one month old lion cub being weighed at Blair Drummond Safari Park near Stirling, Scotland, Thursday October 10, 2013. Weighing in at 5kg, the cub will stay with her mother, Teekay until she is 12 weeks old before they are returned to the pride. (Photo by Andrew Milligan/AP Photo/PA Wire)

Attendees wear a cardboard “Facebox” at the 2017 South By Southwest (SXSW) Interactive Festival at the Austin Convention Center in Austin, Texas, U.S., on Monday, March 13, 2017. The SXSW Interactive Festival features a variety of tracks that allow attendees to explore what's next in the worlds of entertainment, culture, and technology. (Photo by David Paul Morris/Bloomberg)

A light railway train passes through a residential building on March 18, 2017 in Chongqing, China. Chongqing Rail Transit No.2 and a 19-storey residential building have been built across each other. The railway set its Liziba Station on the sixth to eighth floor in the building with noise reduction equipment. (Photo by VCG/VCG via Getty Images)

A woman dressed up for Halloween travels on a Metro train in São Paulo, Brazil on October 30, 2017. (Photo by Cris Faga/Rex Features/Shutterstock)

Venezuelan Hildemaro Ortiz relaxes inside of an abandoned bus in the border city of Pacaraima, Brazil on April 13, 2019. Ten destitute Venezuelan migrants who fled their country's crisis did not get far when they crossed into Brazil: they have been living for three months on an abandoned bus just across the border. (Photo by Pilar Olivares/Reuters)

A participant takes part in a high heel race to protest in favor of gender equality in Monterrey, Mexico on May 12, 2019. (Photo by Daniel Becerril/Reuters)

Labourers push wooden boards before carrying them to construct a temporary pontoon bridge over the Ganges river for the upcoming Hindu festival of Magh Mela in Allahabad on November 24, 2019. The Magh Mela is held every year on the banks of Triveni Sangam – the confluence of the three great rivers Ganga, Yamuna and the mystical Saraswati – in Allahabad during the Hindu month of Magh which corresponds to mid January – mid February. (Photo by Sanjay Kanojia/AFP Photo)