In this Monday, July 24, 2017 photo, a police officer walks in front of a mural during a protest demanding an end to the current pension fund system, in Santiago, Chile. Protesters say the government pension system robs retirees of fair pension payments, and are demanding a new social security system with higher payments. (Photo by Esteban Felix/AP Photo)

In collaboration with the Pennsylvania Department of Transportation, Allegheny College art students repurpose used street signs as art materials to create the PennDOT Road Sign Sculpture Garden in Meadville, Pennsylvania, USA on August 19, 2017. (Photo by Brian Cahn/ZUMA Wire/Rex Features/Shutterstock)

Municipal workers try to retrieve the lid of a manhole to prevent pedestrians from falling in, in Mumbai, India, Wednesday, September 20, 2017. Incessant rainfall in India's commercial capital has affected air and rail traffic, and schools and colleges remained shut for the day. (Photo by Rafiq Maqbool/AP Photo)

An Afghan boy looks through the scope of a toy gun, as other children ride on swings during the first day of the Muslim holiday of Eid al-Fitr, which marks the end of the holy month of Ramadan, in Kabul, Afghanistan June 25, 2017. (Photo by Omar Sobhani/Reuters)

An army dog stands up as retiring soldiers salute their guard post before retirement in Suqian, Jiangsu province, China on November 29, 2017. (Photo by Reuters/China Stringer Network)

Nikolai Vasilyev, 64, dressed as Father Frost, the Russian equivalent of Santa Claus, water-skis along the Yenisei River outside the Siberian city of Krasnoyarsk, Russia December 19, 2017. Vasilyev, former teacher of the Siberian State Aerospace University, constructed the water skis out of plastic foam and designed the sticks to propel him forward, while travelling on the water surface. (Photo by Ilya Naymushin/Reuters)

A devotee looks at the camera as she offers prayers to the setting sun during the “Chhath” festival at Bagmati River in Kathmandu, Nepal on October 26, 2017. (Photo by Navesh Chitrakar/Reuters)

A woman villager cleans garbage in front of her house as flood hits Tanjungsari village in Tasikmalaya, Indonesia, February 23, 2018. (Photo by Adeng Bustomi/Reuters/Antara Foto)