Iraqi soldiers from 9th Armoured Division give drops of water to a dehydrated child rescued earlier by soldiers at the frontline, during the ongoing fighting between Iraqi forces and Islamic State militants near the Old City in western Mosul, Iraq June 13, 2017. (Photo by Erik De Castro/Reuters)

Iranian Arabs who are members of the paramilitary Basij force march in a military parade marking the 35th anniversary of Iraq's 1980 invasion of Iran, in front of the shrine of late revolutionary founder Ayatollah Khomeini, just outside Tehran, Iran, Tuesday, September 22, 2015. (Photo by Vahid Salemi/AP Photo)

A man carries a dog and wades through a flooded street in Chennai, in the southern Indian state of Tamil Nadu, Wednesday, December 2, 2015. Weeks of torrential rains have forced the airport in the state capital Chennai to close and have cut off several roads and highways, leaving tens of thousands of people stranded in their homes, government officials said Wednesday. (Photo by AP Photo)

People dressed in costumes have a break while marching during the Vijanera Festival, in the small village of Silio, northern Spain, Sunday, January 3, 2016. The Vijanera masquerade, of pre-Roman origin, is the first carnival of the year in Europe symbolizing the triumph of good over evil and involving the participation of crowds of residents wearing different masks, animal skins and brightly coloured clothing with its own complex function and symbolism and becoming the living example of the survival of archaic cults to nature. (Photo by Francisco Seco/AP Photo)

An American soldier walks ahead of an MKIV (Mark IV) British-made tank, circa 1918. (Photo by Hulton Archive/Getty Images)

Romanian soldiers take part in a joint military exercise with NATO members, called “Agile Spirit 2015” at the Vaziani military base outside Tbilisi, Georgia, July 21, 2015. Georgian soldiers along with U.S. marines and platoon-size units from Bulgaria, Latvia, Lithuania and Romania are taking part in the exercises at the Vaziani military base outside Tbilisi. (Photo by David Mdzinarishvili/Reuters)

Giant panda Ying Ying rests on a rock in its enclosure while a visitor takes a selfie at Ocean Park in Hong Kong, China, 24 September 2020. An An turned 35 in August. Giant pandas in the wild can live up to 20 years on average, while lifespans of those under human care can reach over 30 years. (Photo by Jerome Favre/EPA/EFE)

A mannequin wearing a face mask and nurse's uniform stands next to a sign supporting the NHS, stands in a field during the Covid-19 pandemic on October 06, 2020 in Northwich, United Kingdom. (Photo by Christopher Furlong/Getty Images)