People dance in a park on a foggy day in Huai'an, Jiangsu province, China October 10, 2017. (Photo by Reuters/China Stringer Network)

In this photo taken in October 1917, provided by Russian State Documentary Film and Photo Archive, a machine gunner looks through a window at his position near the Kremlin in Moscow, Russia. The 1917 Bolshevik Revolution was long before the digital revolution allowed anyone to instantly document events. But the clumsy cameras of the time still caught some images that capture the period's drama. (Photo by Russian State Documentary Film and Photo Archive via AP Photo)

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)

A bull savar (jockey) guides his bulls as he competes in a bull race on the outskirts of Islamabad, Pakistan July 1, 2018. (Photo by Faisal Mahmood/Reuters)

A unidentified woman protests at Broad Street for the pending arrival of Vice President Mike Pence at the Union League, in Philadelphia, Monday, July 23, 2018. Dozens of demonstrators dressed as characters from the novel-turned-TV series “The Handmaid's Tale” descended on downtown Philadelphia to protest Pence’s visit. (Photo by Jose F. Moreno/The Philadelphia Inquirer via AP Photo)

Indian Students of Rabindra Bharati University at the BT Road Campuses Celebrates the Holi, Color Festival on March 09, 2017 in Kolkata.Holi, the popular Hindu spring festival of colours is observed in India at the end of the winter season on the last full moon of the lunar month, and will be celebrated on March 13 this year. (Photo by Debajyoti Chakraborty/NurPhoto)

A Sadhu or a Hindu holy man performs to receive money from pilgrims at a makeshift shelter, before heading for an annual trip to Sagar Island for the one-day festival of “Makar Sankranti”, in Kolkata, India, January 10, 2018. (Photo by Rupak De Chowdhuri/Reuters)