People wearing costumes walk during Halloween in Sierra Madre, California, U.S., October 31, 2017. (Photo by Mario Anzuoni/Reuters)

Employee Jenny Forgie works on an orchid display at Kew Gardens in London, Thursday, February 8, 2018. The 23rd annual Orchid Festival is the first one with a Thailand theme, 66 volunteers worked on the 6,950 exhibited orchids. The festival is open from Feb. 10, 2018 until March 11, 2018. (Photo by Frank Augstein/AP Photo)

The Jet Propulsion Lab team's RoboSimian robot turns on a valve at a simulated disaster-response course during day one of the Defense Advanced Research Projects Agency (DARPA) Robotics Challenge finals in Pomona, California, June 5, 2015. (Photo by David McNew/Reuters)

20-year-old women visit the the Meiji shrine in Tokyo, Japan to celebrate Japan's Coming of Age Day on January 6, 2017. (Photo by Aflo/Rex Features/Shutterstock)

Costumed guests arrive for the “Life Ball” charity event at the Rathaus city hall in Vienna, Austria, 10 June 2017. The 24th Life Ball is a charity fundraiser for HIV and Aids projects. (Photo by Christian Bruna/EPA/EFE)

Competitors take part in the annual Mud Madness event at Foymore Lodge on April 22, 2018 in Portadown, Northern Ireland. The adult version of the event includes two laps of an 8km course through 25 obstacles while the kids event is run over 2kms. The race is in it's eleventh year and is sponsored by McVities Jaffa Cakes and event charity partner Marie Curie together with other numerous charities and fundraising groups. (Photo by Charles McQuillan/Getty Images)

Mae Zelinsky, left, and Betty O'Beda test ammunition on a .30 caliber rifle at a Remington Arms plant on April 30, 1943. Many women took over jobs that were left vacant when men went overseas to fight in World War II. (Photo by AP Photo)

In this photograph taken on June 11, 2018, Chinese artists performs during a Indo-China cultural exchange program in Kolkata, West Bengal, India. (Photo by Dibyangshu Sarkar/AFP Photo)