Russian soldiers write home while serving on the Eastern Front during World War I, circa 1915. (Photo by Hulton Archive/Getty Images)

Soldiers, including two recruits who have brought some chickens, at Victoria prepare to board the train for the battle front. (Photo by Hulton Archive/Getty Images)

A woman and a child walk past the remains of collapsed houses damaged during the April 2015 earthquake, in Bhaktapur, Nepal March 18, 2016. The two devastating earthquakes that struck Nepal last year killed almost 9,000 people across the country. Inside the Kathmandu Valley almost 2,000 died, and some of the area's most important cultural and heritage sites were completely destroyed. As Kathmandu inhabitants prepare to mark the one-year anniversary of the event, thousands are still displaced and millions are living in temporary shelters. (Photo by Navesh Chitrakar/Reuters)

Baraa Melhem plays on her sisters bike at her mothers house on February 2, 2012 in Qalandia, near Ramallah, West Bank. Baraa Melhem was held in captivity in a bathroom by her father for over nine years, and was finally rescued by Palestinian security forces after a family member notified police. (Photo by Ilia Yefimovich/Getty Images)

German field telegraph operators at work in Warsaw. (Photo by Hulton Archive/Getty Images). 1st October 1914

A recruitment drive during the First World War at Trafalgar Square, London. (Photo by Central Press/Getty Images)

NASA astronaut Reid Wiseman and European Space Agency astronaut Alexander Gerst (not shown) works outside the space station's Quest airlock in the first of three spacewalks for the Expedition 41 crew aboard the International Space Station in this NASA image released October 8, 2014. (Photo by Reuters/NASA)

A Chinese tourist visits the Mutianyu Great Wall covered in snow on February 23, 2021 in Beijing, China. Affected by the new coronavirus (COVID-19), the number of visitors to Mutianyu Great Wall in 2020 dropped by about 60%. (Photo by Lintao Zhang/Getty Images)