Soldier boys at Fort Dix, N.J., learn something about guns during their working hours, as they show their girlfriends at a camp dance, December 13, 1940. In front row, playing with the coin amusement gun, from left: Pvt. Tom D'Amato of West Orange; Rose Sinkewicz, behind gun site, of Trenton; Julia Ivans of Trenton, and Pvt. Vernon Landers of Kearney. Back row: Pvts. William Sargent and William Corlies of Philadelphia. (Photo by AP Photo)

A demonstrator shows her arm with the name “Marielle” written on it, as she performs during a protest against the murder of councilwoman Marielle Franco in Rio de Janeiro, Brazil, Tuesday, March 20, 2018. Franco's murder came just a month after the government put the military in charge of security in Rio, which is experiencing a sharp spike in violence less than two years after hosting the 2016 Summer Olympics. (Photo by Leo Correa/AP Photo)

South Vietnamese forces escort suspected Viet Cong officer Nguyen Van Lem (also known as Bay Lop) on a Saigon street February 1, 1968, early in the Tet Offensive. Moments later, Lem was executed by Gen. Nguyen Ngoc Loan, chief of the national police. (Photo by Eddie Adams/AP Photo)

A parrot stuck on a roof for three days greeted firefighters sent to its aid on August 13, 2018 with a four-letter tirade. Jessie, the multi-lingual Macaw, flipped the bird after escaping from her owner's home in Edmonton, north London, UK. When she could not be lured down from a neighbour's roof, firefighters were called out and told to tell the bird “I love you” – to which Jessie replied “I love you back”. But she then ruffled her would-be rescuers' feathers by telling them to “f**k off” before flying off to another nearby rooftop. The foul-mouthed pet also speaks Turkish and Greek according to its owner, but had its own choice words in English for the rescue team. As Jessie wasn't injured, the firefighters, who had been called in by the RSPCA, left her on her perch. The parrot was later reunited with its owner. (Photo by Rex Features/Shutterstock)

Teens got their glad rags on as they hit the town in Newcastle city centre, United Kingdom on August 16, 2018, as they celebrate their exam results. (Photo by North News and Pictures/NNP)

Two Czech Gripen fighter planes demonstrate a flight interception of a Belgian air force transport plane over the Czech Republic, as part of NATO drills on September 12, 2018. (Photo by Francois Lenoir/Reuters)

Soldiers on exercise in Kenya. The image, by Sergeant Dek Traylor, is among the section winners in the UK Army Photographic Competition 2018. (Photo by Sergeant Dek Traylor/PA Wire Press Association)

A girl carries fire wood collected from flood waters in the flood affected Morigaon district of Assam state, India, 25 July 2016. Over half a million people of 15 districts in Assam state have been affected by the current wave of floods. According to the media reports more than 70 relief camps have been set up in the affected districts to provide shelter to the flood affected people. (Photo by EPA/Stringer)