Australian World War Two veterans place crosses and flags at graves before attending the French-British ceremony at the British War cemetery in Bayeux, June 6, 2014. REUTERS/Leon Neal/Pool

The possible surface of TRAPPIST-1f, one of seven newly discovered planets in the TRAPPIST-1 system that scientists using the Spitzer Space Telescope and ground based telescopes have discovered. (Photo by Reuters/NASA/JPL-Caltech)

A raccoon scratches herself on the window sill of the Paige Donnelly Law Firm on the 23rd floor of the UBS Plaza building in St. Paul, Minnesota, U.S., June 12, 2018, in this image obtained from social media. (Photo by Evan Frost/MPR News via Reuters)

Alexandra Mazo, 12, with her cellphone on her way down the mountain after finishing school. The remote mountain village of Pueblo Nuevo has been highly affected by the armed conflict and direct combat between the national army and Farc guerrillas due to its strategic location and the intensive production on coca crops on the surrounding hillsides. (Photo by Mads Nissen/Politiken/The Guardian/Panos Pictures/The Nobel Peace Center)

View of the Villarrica volcano taken from Pucon, some 800 kilometres south of Santiago, showing signs of activity on December 06, 2017. (Photo by Christian Miranda/AFP Photo)

Tactics reminiscent of the early American frontier days are now being used in Vietnam. Lieutenant Commander Donald D. Sheppard, UBN, of Coronado, California, aims a flaming arrow at a bamboo hut concealing a fortified Viet Cong bunker on the banks of the Bassac River, Vietnam on December 8, 1967. (Photo by AP Photo)

At a beauty contest to select the nation's Queen of Height during the first national convention of Tall People's Clubs in New York on July 29, 1949, little Charlie Young, only three feet, eleven inches tall, acting as judge, had a tough time making up his mind for the choice. The national minimum height requirement for women members is 5 feet 10 inches, and for men, 6 feet. (Photo by Robert Kradin/AP Photo)

A tourist poses on the glass-bottom bridge at Zhangjiajie Grand Canyon on August 20, 2016 in Zhangjiajie, Hunan Province of China. The Zhangjiajie Grand Canyon's glass-bottomed bridge welcame its trial operation on Saturday and about 8,000 tourists crowded to view the grand glass bridge. (Photo by VCG/VCG via Getty Images)