South Korea's Amry Special Warfare Command (SWC) soldiers aim their machine guns in a frozen river during a winter exercise in Pyeongchang, South Korea, Thursday, January 8, 2015. About 200 SWC soldiers participated in this routine two-week winter drill. (Photo by Ahn Young-joon/AP Photo)

An Egyptian passenger sits on the locomotive of a train as it leaves Cairo train station in Egypt, Wednesday, October 14, 2015. (Photo by Amr Nabil/AP Photo)

The rising sun illuminates the sky above the spires of a church in Vienna, Austria, November 17, 2015. (Photo by Heinz-Peter Bader/Reuters)

In this Thursday, February 14, 2019, photo, a Transformer's Bumblebee mascot helps a woman carries paper bags at a shopping mall in Handan in north China's Hebei province. U.S. and Chinese envoys are holding a second day of trade talks after the top economic adviser to President Donald Trump said he has yet to decide whether to go ahead with a March 2 tariff increase on imports from China. (Photo by Chinatopix via AP Photo)

A former Gurkha (special forces soldier), Nirmal Purja, takes a selfie at the start of his attempt to scale the world’s 14 highest peaks in seven months to break a 31-year-old record. Nirmal Purja, known as Nims, aims to smash the current record – which stands at seven years, 11 months and 14 days – set by Polish climber Jerzy Kukuczka. On the way, he also plans to defeat at least seven speed world records on mountains over 8,000m high. (Photo by Nirmal Purja/PA Wire Press Association)

A woman, covered in coloured powder, takes part in the 2019 Colour Run, a 5 km run around the Luzhniki Olympic Complex, in Moscow, Russia on June 02, 2019. (Photo by Sefa Karacan/Anadolu Agency/Getty Images)

Over 30 Douglas C-47 Skytrains (Dakotas) making final preparations for flight formation practice before the 75th D-Day Anniversary flight to Normandy in Duxford, England on June 4, 2019. (Photo by UK Air Force Images)

A life-size replica of a Diplodocus dinosaur watches people coming out of the subway in the city center of Bochum, Germany, Monday, August 12, 2019. The exhibition, featuring models of 33 dinosaurs all around the city center, is in Bochum due to the discovery of an 316 million years old dinosaur track found in a stone pit in the city six years ago. (Photo by Martin Meissner/AP Photo)