In this March 22, 1975 file photo, a refugee clutches a baby as a government helicopter gunship carries them away near Tuy Hoa, Vietnam, 235 miles northeast of Saigon. They were among thousands fleeing from Communist advances. AP Photographer Nick Ut will be retiring from the AP in March 2017 after 51 years of taking photographs from the front lines of the Vietnam War to the red carpets of Hollywood. (Photo by Nick Ut/AP Photo)

Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

Chinese-American actress Bai Ling attends “The Key” screening at The Real Experimental Film Festival at Laemmle's Music Hall on November 21, 2014 in Beverly Hills, California. (Photo by Barry King/WireImage)

Winston Leonard Spencer Churchill (1874–1965), British Statesman and Prime Minister inspecting the boys from a training ship. (Photo by Hulton Archive/Getty Images). 1912

Event entertainer Holly Egan poses with a guitar using an angle grinder as Kevin Jay and Nigel Cox spin burning steel wool, sending sparks flying under the A13 in Essex, UK on April 4, 2024. (Photo by Kevin Jay/Picture Exclusive)

A man dressed as Pothuraju, a mythical character, performs rituals during the Bonalu festival in Hyderabad, India, Thursday, June 30, 2022. Bonalu is a month-long Hindu folk festival of the Telangana region dedicated to Kali, the Hindu goddess of destruction. (Photo by Mahesh Kumar A./AP Photo)

Farmers work on a farm near a construction site of new residential buildings in Shanghai, China, February 20, 2016. (Photo by Aly Song/Reuters)

People look at the Harmony of the Seas cruise ship leaving the STX shipyard of Saint-Nazaire, western France, for a three-day test offshore, on March 10, 2016. With a capacity of 6.296 passengers and 2.384 crew members, the Harmony of the Seas, built by STX France for the Royal Caribbean International, is the world's largest ship cruise. (Photo by Loic Venance/AFP Photo)