A hippopotamus is sprayed with water on a hot summer day at Anna National Zoological Park in Chennai, India on April 26, 2017. (Photo by Arun Sankar/AFP Photo)

A pupil of the Dao ethnic tribe returns home from school along a hillside path at Suoi Thau village in Hoang Su Phi district of Vietnam's northern province of Ha Giang, located at the border with China, September 18, 2015. (Photo by Reuters/Kham)

In this January 12, 2016 photo, an abandoned boat lies on the dried up lake bed of Lake Poopo, on the outskirts of Untavi, Bolivia. Drought caused by the recurrent El Nino meteorological phenomenon is considered the main driver of the lake's demise. Along with glacial melting, authorities say another factor is the diversion of water from Poopo's tributaries, mostly for mining but also for agriculture. (Photo by Juan Karita/AP Photo)

Pakistani street performers sit around fire waiting for customers on a chilly evening in Rawalpindi, Pakistan, Wednesday, February 10, 2016. (Photo by B.K. Bangash/AP Photo)

People sit on a cart with a camel tied to it during “Temeenii bayar”, the Camel Festival, in Dalanzadgad, Umnugobi aimag, Mongolia, March 6, 2016. On the steppes of the Gobi Desert, the crowd urges on Bactrian camels laden down with all that's needed to build and live in a traditional Mongolian tent. Guinness World Records classes the 15 km race thatÕs part of the two-day festival as the largest camel race in the world, drawing 1,108 participants. The winning camel romped home in 35 minutes and 12 seconds, according to the records website. (Photo by B. Rentsendorj/Reuters)

Laborers work on scaffolding near a full-scale replica of the Sphinx at an unfinished movie and animation tourism theme park, in Chuzhou, Anhui province, March 27, 2015. (Photo by Reuters/China Daily)

A tufted puffin is seen in Kamchatka Territory, Russia on July 17, 2018. (Photo by Yuri Smityuk/TASS)

North Korean bodyguards run along a limousine transporting Kim Jong Un upon his arrival in Dong Dang, Vietnam, February 26, 2019. The second meeting of the US President and the North Korean leader, running from 27 to 28 February 2019, focuses on furthering steps towards achieving peace and complete denuclearization of the Korean peninsula. (Photo by Reuters/Stringer)