An Iranian girl walks at the Tochal ski resort, in north of Tehran, Iran on December 12, 2019. (Photo by Nazanin Tabatabaee/WANA via Reuters)

Joe Deedon, president of TAC ONE Consulting, demonstrates searching for a shooter in a middle school during an Active Shooter Response course offered by TAC ONE in Denver April 2, 2016. According to TAC ONE, the course, which is offered for the first time to concealed weapons permit carrying civilians, is designed at preparing people to effectively save lives prior to the arrival of law enforcement at an active shooter incident. (Photo by Rick Wilking/Reuters)

For more than three years, Ukraine has been plagued by a conflict between the eastern secessionist territories and the Kiev government. Demonstrations by pro-Russian parties that oppose the current government first began in 2014 - and now, over 10,000 people have died, many of them civilians. These images portray a generation caught between war and peace. Many of them were born into the civil conflict dominating the country and are disorientated about their place in the world. Here: Youths during a party organised on a decommissioned bridge in Kiev. (Photo by Aude Osnowycz/The Guardian)

Brave slackliners have been pictured walking the ropes above Rio de Janeiro, Brazil on August 15, 2016, with the half a mile drop showing the city in all its glory. The stunning shots show the daredevils tread across an eighty-two-foot-long high line on Pedra da Gvea mountain with an amazing sunrise illuminating the city landscape behind. (Photo by Rafael Moura/Caters News Agency)

Collided passenger train cars are seen in Taebaek, South Korea, Tuesday, July 22, 2014. Two passenger trains collided head-on in eastern South Korea on Tuesday afternoon, killing one passenger and injuring dozens, fire officials said. (Photo by AFP Photo/Yonhap)

A 10-year-old pet goldfish named George undergoes veterinarian Tristan Rich's scalpel to remove a life-threatening head tumor in this handout picture taken September 11, 2014 and provided to Reuters by the Lort Smith Animal Hospital in Melbourne, Australia. In a 45-minute long procedure described by Rich as “fiddly”, the fish was sedated by water laced with anaesthetic, the tumour removed and the wound sealed with tissue glue followed by antibiotics and painkillers. (Photo by Reuters/Lort Smith Animal Hospital)

Leonhard Nienbling is shown with his 6-month old pet baboon Jackl, who holds a 6-month old kitten, its playmate, June 29, 1952. Niebling has quite an animal collection at his home in Zirndorf, Germany. (Photo by Heinrich Sanden/AP Photo)

“The young adult humpback could have a plot waiting for it at a whale graveyard hidden in bushland at Garrigal Garigal National Park”. – Janet Fife-Yeomans via AdelaideNow

Photo: People gather on the beach to see the carcass of a male sub-adult humpback whale that washed up at New Port Beach overnight at Newport Beach overnight on August 1, 2012 in Sydney, Australia. (Photo by Brendon Thorne)