A man stands at a passenger train damaged in a collision with a freight train in Moscow region May 20, 2014. The passenger train on its way to Moldova collided with a freight train near Moscow on Tuesday, killing at least four people and injuring 15, a spokeswoman for Russia's Emergencies Ministry said. The reason for the collision, near the town of Naro-Fominsk 55 km (34 miles) southwest of Moscow, was not immediately clear. (Photo by Grigory Dukor/Reuters)

This picture taken on July 15, 2014 shows a bridge submerged in floodwaters in the ancient town of Fenghuang, central China's Hunan province. Rainstorms lashed central China's Hunan Province and southwest China's Guizhou Province, affecting over 1 million people and flooding a historical town, state media reported. (Photo by AFP Photo)

In this October 15, 2014 file photo, Katsu Nakamura, sky division manager for Yamaha USA, moves the RMax unmanned helicopter into position before a demonstration of its aerial application capabilities at the University of California, Davis' Oakville Station test vineyard in Oakville, Calif. Researchers at UC Davis have been studying the effectiveness of the drone's ability for spraying pest control and nutritional materials on the test vineyard in California's Napa Valley. (Photo by Rich Pedroncelli/AP Photo)

Camp director and “duck walk” inventor (Rodin Gilbert Flores, 2nd R) teaches aspiring beauty queens how to “duck walk” at a beauty boot camp in Manila in this picture taken on March 8, 2015. From wading in muddy Philippine rice paddies, former housemaid Janicel Lubina now struts down runways for the country's top designers, and is poised to be crowned among the world's most beautiful. Lubina is a star recruit in one of Manila's beauty pageant boot camps, where shy, lanky teenage girls from remote farming provinces are transformed into poised Barbie dolls who can preach about world peace in six-inch heels. (Photo by Noel Celis/AFP Photo)

Girls of the Long Horn Miao ethnic minority group wear headdresses as they prepare gather for Tiaohua or Flower Festival as part of the Lunar New Year on February 6, 2017 in Longga village, Guizhou province, southern China. (Photo by Kevin Frayer/Getty Images)

An alligator is skinned at All American Gator August 16, 2006 in Pembroke Park, Florida. The company processes gators for their skins, meat and trophies and was at full capacity a day after the start of gator hunting season. This year more than 4,000 licenses were sold with each license allowing hunters to kill two gators. The hunt has been expanded by 41 days over previous years, running August 15 to November 1. (Photo by Joe Raedle/Getty Images)

A dog dives during a pet dog swimming contest at the Taoyuan Pet Center on July 31, 2005 in Chengdu of Sichuan Province, southwest China. Over 30 dogs have attended the match. According to state media, with the country's pet population growing fast, analysts predict that the market potential for the “pet economy” in China could reach a minimum of RMB 15 billion (about USD 1.85 billion). (Photo by China Photos/Getty Images)

Plastinated human corpses posed to look like poker players stand on display at the Body Worlds exhibition on April 27, 2011 in Berlin, Germany. The exhibition, which features human and animal corpses plastinated by Gunther von Hagens, focuses on the role of the heart. It will be open to the public at the Postbahnhof from April 27 to August 14. (Photo by Sean Gallup/Getty Images)