Technicians check a CRH high-speed train at Shanghai Hongqiao High-speed train base on December 28, 2011 in Shanghai, China. China's railway stations have started today to sell tickets for the 2012 Spring Festival travel season scheduled to run between January 8th and February 16th, centred around the Chinese New Year which this year falls on January 23rd. (Photo by ChinaFotoPress/Getty Images)

U.S. Army soldiers with the 1st Battalion, 501st Infantry Regiment deployed to Combat Outpost Sabari, Afghanistan scan their area as they begin a multi-day air assault mission near the Pakistani border of eastern Afghanistan's Khost province May 2, 2012. (Photo by Staff Sgt. Joshua L. DeMotts/U.S. Air Force)

Women wearing sunglasses pose for a group photo at a park in Beijing in 1980. (Photo by Reuters/China Daily)

A man photographs the main engines of the space shuttle orbiter Discovery on display at the Udvar-Hazy Smithsonian National Air and Space Annex Museum in Chantilly, Virginia August 28, 2015. Shuttle Discovery had 27 years of service and flew 39 times before being retired in 2011. (Photo by Gary Cameron/Reuters)

Lady Gaga performs at Radio 1's Big Weekend 2011 at Carlisle Airport on May 15, 2011 in Carlisle, England. (Photo by Dave Hogan/Getty Images)

Grinders are on display for sale during the HempCon 2011 Medical Marijuana Expo at the Los Angeles Convention Center on August 26, 2011 in Los Angeles, California. The three-day event includes exhibits, evaluation services, legal services, equipment, and accessories. (Photo by Kevork Djansezian/Getty Images)

A model showcases designs by Twenty Seven Names in a photograph as part of New Zealand Fashion Week 2011 at a Newton Gallery on August 30, 2011 in Auckland, New Zealand. (Photo by Sandra Mu/Getty Images)

A model showcases “The Bride” by Stephane Rolland on the catwalk as part of Women's Fashion Week Haute Couture program at Marina Bay Sands on October 30, 2011 in Singapore. (Photo by Chris McGrath/Getty Images)