Jordanian policewomen train in unarmed combat in the training city August 21, 2008 in Muwaqqar, east of Amman, Jordan. A women's police academy opened in Amman in 1972 making Jordan the first Arab country to admit women to its police services. Jordanian policewomen work as personalities' guards, special security operations and traffic policewomen including motorcycling among other professions. (Photo by Salah Malkawi/Getty Images)

Children play at the Ryoji Ikeda exhibition “the transfinite” at the Park Avenue Armory on June 10, 2011 in New York City. The audio visual installation, which will close after tomorrow, features two back-two-back screens displaying a continual loop of sounds, fragments of numbers and strobe-lit patterns that echo the Japanese artist's interest in mathematics, the subconscious and the digital world. (Photo by Spencer Platt/Getty Images)

School boys who attend Sri Lankan traditional dance training wait for their graduation ceremony at a Buddhist temple in Colombo, Sri Lanka January 23, 2017. (Photo by Dinuka Liyanawatte/Reuters)

Paramedics carry an injured woman out from a subway station after a rush-hour subway train derailment, to be transported by a medical helicopter in Moscow, Russia, on Tuesday, July 15, 2014. A rush-hour subway train derailed in Moscow Tuesday, killing 20 people and injuring at least 150, emergency officials said. Several cars left the track in the tunnel after a power surge triggered an alarm, which caused the train to stop abruptly. (Photo by Ivan Sekretarev/AP Photo)

A feeder trains a Siberian tiger cub at Erdaohe Tiger Park July 2, 2006 in Antu County of Yanbian Chaoxian Autonomous Prefecture, Jilin Province, China. About 15 artificially-fed Siberian tigers from Harbin Siberian Tiger Park are being trained to develop their ability to live in the wild. The wild Siberian tiger is listed as one of the most endangered species in the world, with its existing number estimated at around 400 worldwide, mainly in the northeastern part of China and the Far East of Russia. Reportedly there are more than 1,300 Siberian tigers which have been raised in China. (Photo by China Photos/Getty Images)

Young girls practice acrobatic skills in the Sichuan Provincial Art School July 14, 2008 in Chengdu of Sichuan Province, China. (Photo by China Photos/Getty Images)

Stuart Craig of Washington tries out a Sig Sauer 1911 model Scorpion pistol at the Sig Sauer booth at the National Shooting Sports Foundation's 34th annual Shooting, Hunting, Outdoor Trade (SHOT) Show at the Sands Expo and Convention Center January 17, 2012 in Las Vegas, Nevada. The SHOT Show is the largest annual gathering of shooting professionals with more than 1,600 exhibitors and 30,000 attendees expected. (Photo by Ethan Miller/Getty Images)