Chinese artists perform on stage during the opening ceremony of the International Horticultural Exposition 2011 at the Exposition Park on April 28, 2011 in Xi'an, Shaanxi Province of China. The World Horticultural Exposition 2011 will be held in Xi'an from April 28 to October 22. (Photo by ChinaFotoPress/Getty Images)

A rugby fan adjusts his latex mask at the rugby sevens tournament in Hong Kong on March 29, 2014. (Photo by Philippe Lopez/AFP Photo)

A snowflake rests on black velvet after a snowfall in Knoxville on Tuesday, January 28, 2014. (Photo by Adam Lau/News Sentinel)

Boys play with a drainage culvert used for flood control in Las Pinas, Metro Manila February 28, 2016. (Photo by Erik De Castro/Reuters)

A dancer performs as visitors take pictures at an auto show in Tianjin, China April 28, 2016. (Photo by Reuters/Stringer)

A participant runs through foam during the Love Foam Run race in Hsinchu, Taiwan May 29, 2016. (Photo by Tyrone Siu/Reuters)

Atmosphere at the 84th Annual Hollywood Christmas Parade held at The Roosevelt Hotel on November 29, 2015 in Hollywood, California. (Photo by Zuma Wire/Rex Shutterstock)