A women wearing a mask to protect from extreme smog visits the Tiananmen Gate in Beijing December 8, 2015 as China's capital issues its first ever "red alert" for pollution. (Photo by Damir Sagolj/Reuters)

The winners in the third annual drone photography awards have been announced. Organised by the social network Dronestagram, the competition attracted more than 6,000 entries from amateur and professional drone enthusiasts across the world. Here: First place in the travel category went to the Basilica of Saint Francis of Assisi in Italy. (Photo by Francesco Cattuto)

France's Alize Cornet celebrates scoring a point in the first round match of the French Open tennis tournament against Italy's Roberta Vinci at the Roland Garros stadium, in Paris, France, Monday, May 25, 2015. (Photo by Christophe Ena/AP Photo)

These Arab recruits line up in a barracks square in the British Mandate of Palestine, on December 28, 1940, for their first drill under a British solider. Some 6,000 Palestinian Arabs signed up with the British Army during the course of World War II. (AP Photo)

First lady Michelle Obama (R), joined by daughters Sasha Obama (C) and Malia Obama, is presented with the official White House Christmas Tree on November 25, 2011 in Washington, DC. The tree, a 19-foot-tall balsam fir, was grown on Schroeder's Forevergreens farm near Neshkoro, Wisconsin. (Photo by Brendan Hoffman/Getty Images)

Three men display their tattoos during the International Malaysia Tattoo Expo in Kuala Lumpur on November 29, 2019. The international tattoo expo is held for the first ime in Kuala Lumpur celebrating that art of tattoo and gathering over a hundred tattoo artists from 40 countries. (Photo by Mohd Rasfan/AFP Photo)

Cheerleaders wearing face masks due to the outbreak of the coronavirus disease (COVID-19) are seen at the first professional baseball league game of the season at Taoyuan International baseball stadium in Taoyuan city, Taiwan, April 11, 2020. (Photo by Ann Wang/Reuters)

A showgirl in a face mask stands by the door at the reopening of Bally's Las Vegas hotel and casino, Thursday, July 23, 2020, in Las Vegas. The casino reopened for the first time since March following a closure to prevent the spread of the coronavirus. (Photo by John Locher/AP Photo)