A line of soldiers firing handguns during a training session, circa 1920. (Photo by Keystone). P.S. All pictures are presented in high resolution.

The moon rises behind Reunion Tower in downtown Dallas, Sunday evening, November 13, 2016. On Monday the supermoon will be the closest full moon to earth since 1948, and it won't be as close again until 2034. (Photo by Tom Fox/The Dallas Morning News via AP Photo)

“Bazooka”, a one year old stray cat, is treated at the SPCA (Society for Prevention of Cruelty to Animals) clinic in Tel Aviv, Israel, 06 January 2016. Bazooka arrived at the clinic in critical condition after he went through severe abuse with bruises all over his body and painted with pink oxidation. The Israeli street cat population is estimated to be about two million. Without enough financial support from the state, animal rights organizations find it difficult to keep the up with the pace when it comes to spaying and neutering feral cats, causing the population to grow. (Photo by Abir Sultan/EPA)

A boy jumps over a puddle of water on the outskirts of Havana, Cuba March 21, 2016. (Photo by Ueslei Marcelino/Reuters)

A policeman reacts during a clash with protestors during a protest against the proposed changes to France's working week and layoff practices, in Lyon, central France, Thursday, April 28, 2016. French protesters are back on the streets over proposed reforms to the country's labor rules and strikers have forced cancellations and delays at two airports serving Paris. (Photo by Laurent Cipriani/AP Photo)

Filipino firemen extinguish a burning vehicle during an earthquake preparedness drill in Makati city, south of Manila, Philippines, 22 June 2016. Thousands of people participated in the Metro Manila earthquake drill to prepare residents of nearly 12 million for a feared magnitude-7.2 quake that could kill thousands and displace millions, Emerson Carlos head of the Metropolitan Manila Development Authority (MMDA) said. Philippines sits on the Pacific Ring of Fire, an area prone to seismic shifts that spark earthquakes and volcanic activity. (Photo by Francis R. Malasig/EPA)

A woman wears a face mask in the part of the city near neighbourhoods known for burning coal for heating in Ulaanbaatar, Mongolia January 26, 2017. Not many people in Ulaanbaatar wear masks to protect themselves against pollution. (Photo by B. Rentsendorj/Reuters)

In this Saturday, April 8, 2017 photo, a keeper walks camels to the Al Marmoom Camel Racetrack, in al-Lisaili about 40 km (25 miles) southeast of Dubai, United Arab Emirates. Camel racing is a big-money sport and fast thoroughbreds can fetch well over a million dollars. As rising temperatures across Gulf Arab countries signal the end of the winter camel racing season, Dubai is wrapping up its races with the annual Al Marmoom Heritage Festival that has drawn thousands of camels from across the oil-rich Gulf. (Photo by Kamran Jebreili/AP Photo)