A riot policeman watches as a police vehicle burns in Braamfontein, Johannesburg, South Africa, Tuesday, October 25, 2016. Rioters in South Africa set a police vehicle on fire Tuesday and stoned vehicles near a Johannesburg university that has been the scene of sometimes violent protests by students demanding free education. The violence broke out in streets near the University of the Witwatersrand at around the same time that student protesters met and marched off the campus, South African media reported. (Photo by Yeshiel Panchia/AP Photo)

A car “crashed” into the ground at Hackescher Markt in Berlin, Germany on November 15, 2016, ahead of the launch of Jeremy Clarkson, Richard Hammond and James May's new show, “The Grand Tour”, on Amazon Prime Video, on Friday. (Photo by Clemens Bilan/Getty Images for Amazon Prime Video)

A coach wipes away tears and comforts a girl who was feeling tired during gymnastics lessons at the Shanghai Yangpu Youth Amateur Athletic School in Shanghai, China, May 4, 2016. (Photo by Aly Song/Reuters)

Participants dance and climb on an art installation as approximately 70,000 people from all over the world gather for the 30th annual Burning Man arts and music festival in the Black Rock Desert of Nevada, U.S. August 31, 2016. (Photo by Jim Urquhart/Reuters)

A man pours water on his camel on a hot summer day in Ahmedabad, India, May 18, 2017. (Photo by Amit Dave/Reuters)

People play with foam at a water park in Yantai, Shandong province, China June 16, 2107. (Photo by Reuters/Stringer)

Two sheep fight in a competition in Zhangjiakou, Hebei province, China on August 1, 2017. (Photo by Reuters/China Stringer Network)

Filipinos riding on makeshift carts cross over an overflowing dam during a downpour in Las Pinas city, south of Manila, Philippines, 05 September 2017. According to the latest forecast from the Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) state weather bureau, typhoon signals were raised over Northern Luzon brought by a tropical storm (local name: Tropical Storm Kiko) and warned fisherfolks and small seacrafts not to venture onto the sea due to big waves. (Photo by Francis R. Malasig/EPA/EFE)