Riot security forces clash with demonstrators as a motorcycle is set on fire during a protest against Venezuelan President Nicolas Maduro's government in San Cristobal, Venezuela May 29, 2017. (Photo by Carlos Eduardo Ramirez/Reuters)

Thai Princess Bajrakitiyabha (R) and Princess Sirivannavari Nariratana take part in the funeral procession for the late Thai king Bhumibol Adulyadej in Bangkok on October 26, 2017 A sea of black- clad mourners massed across Bangkok' s historic heart early on October 26 as funeral rituals began for King Bhumibol Adulyadej, a revered monarch whose passing after a seven- decade reign has left Thailand bereft of its only unifying figure. (Photo by Damir Sagolj/Reuters)

In this April 23, 2015 photo, friends Jia Haixia, left, and Jia Wenqi work to plant a tree in a field in Yeli village near Shijiazhuang city in northern China's Hebei province. For the past 13 years, Jia Wenqi, who has no arms, and Jia Haixia, who is blind, have worked together to plant and water more than 12,000 trees near their village. (Photo by Helene Franchineau/AP Photo)

Indian labourers carry clay bricks to a brick kiln in Farakka, in the Indian state of West Bengal, on April 3, 2019. (Photo by Xavier Galiana/AFP Photo)

Alluvial Fan, China. A vast alluvial fan blossoms across the desolate landscape between the Kunlun and Altun mountain ranges that form the southern border of the Taklimakan Desert in China’s XinJiang Province. Image taken by the ASTER instrument on NASA’s Terra satellite on May 2nd, 2002. (Photo by NASA/GSFC/USGS EROS Data Center)

Russian army soldiers, dressed in WWII era uniforms, march along the Red Square during a general rehearsal for the Victory Day military parade which will take place at Moscow's Red Square on May 9 to celebrate 70 years after the victory in WWII, in Moscow, Russia, Thursday, May 7, 2015. (Photo by Ivan Sekretarev/AP Photo)

A C-17 Globemaster III crew prepares an air refueling mission September 27, 2012, at Joint Base Charleston, S.C. (Photo by Airman 1st Class Matthew J. Bruch/U.S. Air Force photo)

A dinosaur robot produced by Tyco Electronics Japan G.K. is controlled by a smartphone at CEATEC (Combined Exhibition of Advanced Technologies) Japan 2014 held at at Makuhari Messe in Chiba, east of Tokyo, Japan, 07 October 2014.With a Sharp Aquos ZETA mobile phone model, users can make the 6.5-meter (21 feet, 4 inches) long, 2.1-meter (6 feet, 11 inches) tall dinosaur robot to walk forward and backward, jump, move its head, hands and legs up and down, left and right, open and close its mouth by touching the screen panel and make it bark by shaking the handheld. (Photo by Kimimasa Mayama/EPA)