Protesters run for cover after riot police fired tear gas towards the bridge they were climbing down to the road below, to escape from Hong Kong Polytechnic University campus and from police, in Hung Hom district in Hong Kong on November 18, 2019. Dozens of Hong Kong protesters escaped a besieged university campus on November 18 by lowering themselves on a rope from a footbridge to a highway, AFP video showed. Once on the road they were seen being picked up by waiting motorcyclists. (Photo by Anthony Wallace/AFP Photo)

A tourist carries her luggage in a flooded St. Mark's Square, in Venice, Wednesday, November 13, 2019. The high-water mark hit 187 centimeters (74 inches) late Tuesday, Nov. 12, 2019, meaning more than 85% of the city was flooded. The highest level ever recorded was 194 centimeters (76 inches) during infamous flooding in 1966. (Photo by Luca Bruno/AP Photo)

A car drives through a flooded road following heavy rain in Gaza City on December 27, 2019. (Photo by Mohammed Abed/AFP Photo)

Dhofar Region, Oman. Much of Oman is desert, but the Arabian Sea coast in the Dhofar region represents a startling difference in climate. This coastal region catches the monsoon rains, or khareef, during the summer months. Drenching rains fall primarily on the mountainous ridge that separates the lush, fertile areas along the coast from the arid interior, recharging streams, waterfalls and springs that provide plentiful water supplies in the fertile lowlands for the remainder of the year. Image taken by Landsat 5 on April 2, 2005. (Photo by USGS/NASA)

A young protester takes part in a protest near Tahrir Square to call for the fall of Islamist President on January 24, 2012 in Cairo. (Photo by Mohammed Abed/AFP Photo via The Atlantic)

A woman reacts as anti-government protesters place a dead body on a stretcher after violence erupted in the Independence Square in Kiev, in this February 20, 2014 file photo. (Photo by Vasily Fedosenko/Reuters)

Kia Vue of St. Paul sports long nails at the Minnesota Hmong New Year celebration Saturday, November 29, 2014, at the Saint Paul RiverCentre in St. Paul, MN. The annual Minnesota Hmong New Year celebration will be held at the Saint Paul RiverCentre November 28–30. Hmong New Year has a deep cultural significance to the Hmong community. It is a celebration of accomplishments during the past year and a time to welcome a new beginning. (Photo by David Joles/Star Tribune)

Children play football in front of an abandoned train compartment next to a railway track in Dhaka, in this May 29, 2014 file photo. (Photo by Andrew Biraj/Reuters)