A novice monk holds a book during an inauguration ceremony at Jogye temple in Seoul, May 11, 2015. Ten children on Monday were given the opportunity to experience life as Buddhist monks by staying at the temple until Buddha's birthday in two weeks. The writing on the book reads, “Novice Monk Prayer”. (Photo by Thomas Peter/Reuters)

An Iranian woman gestures as she celebrates in the streets following a nuclear deal with major powers, in Tehran July 14, 2015. Overcoming decades of hostility, Iran, the United States, and five other world powers struck a historic accord Tuesday to check Tehran's nuclear efforts short of building a bomb. The agreement could give Iran access to billions in frozen assets and oil revenue, stave off more U.S. military action in the Middle East and reshape the tumultuous region. (Photo by Reuters/TIMA)

Doris Dean of Chicago, Ill., sits with her gun shortly after she won a 50 meter, 40-shot event for women with a perfect 400 score at the National Rifle Association (NRA) matches at Camp Perry, near Toledo, Ohio, September 7, 1941. (Photo by AP Photo/DW)

Singers Chris Daughtry and Rachel Platten attend the 2017 Billboard Music Awards at T-Mobile Arena on May 21, 2017 in Las Vegas, Nevada. (Photo by Chris Polk/BBMA2017/Getty Images for DCP)

Planned improvements to Rio’s favelas have meant increases in rent, forcing the poorest families into squatting in unoccupied buildings. Photographer Tariq Zaidi visits the Mangueira community favela, less than 1km from the showpiece Maracanã stadium, to see what life is like for the women living there. Here: Victoria, 12, at her home in Mangueira. (Photo by Tariq Zaidi/The Guardian)

The fourth annual BigPicture Natural World Photography Competition aims to celebrate the diversity of life on Earth, and encourages people to protect and conserve it. Here: “The Salmon Catchers”. Terrestrial Wildlife. To capture this view of a mother grizzly bear and her cub, photographer Peter Mather set up a camera trap on a log that he knew the bears tended to traverse while fishing for salmon, in the Yukon River watershed in Canada. (Photo by Peter Mather/BigPicture Natural World Photography Competition 2017)

This 1950s photo provided by the Estate of Vivian Maier and John Maloof Collection shows Maier in a self-portrait as she looks into a storefront wearing a hat in New York. New research about Maier shows the enigmatic Chicago nanny was obsessive about honing her skills as a photographer starting in 1950. (Photo by Vivian Maier/Estate of Vivian Maier and John Maloof Collection via AP Photo)

In this October 8, 2017, photo, Emily Lynch reacts to hitting her first clay target during a training session for the Trigger Warning Queer & Trans Gun Club in Victor, N.Y. A gay, lesbian and transgender group concerned that extremists have become more emboldened and dangerous have decided to take up arms. The gun club meets once a month to shoot long guns in a field in upstate New York. (Photo by Adrian Kraus/AP Photo)