U.S. President Donald Trump boards Air Force One to depart for Vietnam from Beijing Airport in Beijing, China on November 10, 2017. (Photo by Jonathan Ernst/Reuters)

A detailed view of the BMW 1600 during the The 40th Antwerp Classic Salon run by SIHA Salons Automobiles and held at Antwerp EXPO Halls on March 3, 2017 in Antwerpen, Belgium. (Photo by Dean Mouhtaropoulos/Getty Images)

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 common kingfisher sits on a branch of a tree after catching an insect in Allahabad, India, Sunday, July 9, 2017. The common kingfisher is a highly territorial bird that has to eat nearly sixty percent of its bodyweight every day. (Photo by Rajesh Kumar Singh/AP Photo)

A cyclist drives past a flowering rapeseed field not far from the small Bavarian village of Schoengeising, near Munich, during a nice, warm sunny weather day on May 17, 2017. (Photo by Christof Stache/AFP Photo)

Actors wrapped in blankets react at the set of the post-apocalyptic movie “Zombie Era” at an abandoned factory complex in Langfang, Hebei province, China December 16, 2016. (Photo by Damir Sagolj/Reuters)

A visitor feeds a food pellet to a giraffe in the Giraffe Centre in Nairobi, Kenya January 15, 2017. (Photo by Goran Tomasevic/Reuters)

An American soldier walks ahead of an MKIV (Mark IV) British-made tank, circa 1918. (Photo by Hulton Archive/Getty Images)