View of an American marine as he lies in a foxhole and whistles at a husky, one of the scouting dogs used during the landing on Guam, August 1944. (Photo by W. Eugene Smith/Time & Life Pictures/Getty Images)

This photo taken on June 19, 2017 shows Indian yoga teacher Mahesh Yogiji attempting a world record for the longest yoga session in Ahmedabad, ahead of International Yoga Day on June 21. According to Guiness World Records, the longest yoga marathon undertaken by a man lasted 69 hours and was achieved by V Gunasekaran in Tamil Nadu in June 2016. (Photo by Sam Panthaky/AFP Photo)

An air tanker drops fire retardant on flames as firefighters continue to battle against the Detwiler fire in Mariposa, California on July 19, 2017. The Detwiler fire is currently at 7 percent containment and has burned more than 45,000 acres and destroyed eight structures. (Photo by Josh Edelson/AFP Photo)

A Palestinian boy carries dates from palm trees during harvest season in southern Gaza September 25, 2016. (Photo by Ibraheem Abu Mustafa/Reuters)

Airmen and their Japanese dates “do” the town together, visiting the local points of interest. Almost every community in Japan has it's famous shrines and parks. Tachikawa boasts beautiful environment. Girls are wearing western dress, May 1952. (Photo by National Archives and Records Administration)

Women dressed as a rabbit and a fox, who pose for pictures with tourists, walk in central Kiev, Ukraine April 4, 2018. (Photo by Gleb Garanich/Reuters)

Italian actress Zaina Dridi walks the red carpet for “Carol” during the 10th Rome Film Fest at Auditorium Parco Della Musica on October 22, 2015 in Rome, Italy. (Photo by PA Press Association Images)

Three workers demonstrating the different types of gas masks used in mine rescue work. (Photo by Fox Photos/Getty Images). December 1925