Russian President Vladimir Putin aims a sniper rifle during a visit to the Patriot military exhibition center outside Moscow, Russia, Wednesday, September 19, 2018. Putin chaired a meeting that focused on new arms programs. (Photo by Alexei Nikolsky/Sputnik/Kremlin Pool Photo via AP Photo)

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

People on inflatable boats enjoy the weather on the Lake Lucerne in Sisikon, Switzerland, August 5, 2018. (Photo by Denis Balibouse/Reuters)

In this Friday, December 4, 2018 photo, a half sunken cruise ship lays on its side, in the Gulf of Elefsina, west of Athens. Dozens of abandoned cargo and passenger ships lie semi-submerged or completely sunken around the Gulf of Elefsina, near Greece’s major port of Piraeus. Now authorities are beginning to remove the dilapidated ships. Some of them have been there for decades, leaking hazards like oil into the environment and creating a danger to modern shipping. One expert calls the abandoned ships “an environmental bomb”. (Photo by Thanassis Stavrakis/AP Photo)

First place, The Beauty of Plants. “There are many stages of lotus growth on display at the Aquatic Gardens, but to come across twotwisted dancing stems of nelumbo nucifera was unexpected and quite magical”. (Photo by Kathleen Furey/The Guardian)

Indonesian soldiers take part in a handling riots practice ahead of the elections at their military home base in Banda Aceh, Aceh province on April 9, 2019. (Photo by Chaideer Mahyuddin/AFP Photo)

Jaime “Ka Diego” Padilla (R), spokesperson of the Melito Glor Command of the New People's Army (NPA), and Ka Kathryn (Comrade Kathryn) (L) react during their 50th founding anniversary celebration at an undisclosed location in the mountains of Sierra Madre, Philippines, 31 March 2019. (Photo by Alecs Ongcal/EPA/EFE)

A Sudanese girl with half painted face watches as protesters demonstrate outside the defense ministry compound in Khartoum, Sudan, April 25, 2019. (Photo by Umit Bektas/Reuters)