Fighters of the Free Syrian Army fire an anti-aircraft weapon in the rebel-held Mashhad area in southeastern Aleppo, on December 12, 2016, as they battle Syrian government forces during an operation to retake the embattled city. The crucial battle for Aleppo entered its “final phase” after Syrian rebels retreated into a small pocket of their former bastion in the face of new army advances. The retreat leaves opposition fighters confined to just a handful of neighbourhoods in southeast Aleppo, the largest of them Sukkari and Mashhad. (Photo by AFP Photo/Stringer)

Adrienne Sipe (L) and Brooke Gilliam of Washington D.C. leap off a snow podium they made near the U.S. Capitol in Washington February 13, 2014. A deadly and intensifying winter storm packing heavy snow, sleet and rain pelted a huge swath of the U.S. East Coast on Thursday, grounding flights and shuttering schools and government offices. (Photo by Kevin Lamarque/Reuters)

Indigenous Sahrawi girls play on an improvised see-saw at a refugee camp of Boudjdour in Tindouf, southern Algeria March 3, 2016. UN Secretary General Ban Ki-moon is scheduled to visit the Sahrawi refugees in south-west Algeria's Tindouf region. (Photo by Zohra Bensemra/Reuters)

A baby Black-crowned Night Heron squawks in its incubator while being cared for at City Wildlife rescue and rehabilitation center in Washington, DC on May 31, 2017. The heron is one of several that have been brought to CW by the staff at The National Zoo over the past few years. (Photo Linda Davidson/The Washington Post)

Festival goers arrive for the Glastonbury festival at Worthy Farm, in Somerset, England, Thursday, June 23, 2016. (Photo by Guy Bell/Rex Features/Shutterstock)

A jogger runs on the bank of Donaukanal channel in central Vienna, Austria, September 5, 2016. (Photo by Heinz-Peter Bader/Reuters)

Visitors look up at mock-ups of dinosaur skeletons inside the Museum of Natural History in Pyongyang on September 28, 2016. (Photo by Ed Jones/AFP Photo)

A woman wears a Yao bridal headdress in Hezhou, Guangxi, China on January 6, 2021. (Photo by Sipa Asia/Rex Features/Shutterstock)