The “Assignments” exhibition is an annual chance to see the top images by UK photojournalists, as chosen by the British Press Photographers’ Association. Here: Wales’s Cory McKenna dominates Micol DiSegni during their fight at Cage Warriors 97 in Cardiff, 29 September 2018. (Photo by Chris Fairweather/Huw Evans Agency)

Maria Menounos and Derek Hough sit courtside as the Celtics play the Lakers in Los Angeles, March 2012. (Photo by Lucy Nicholson/Reuters)

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)

In this March 3, 2015 photo, a group of California sea lions rest on a large bouy in the San Ignacio lagoon, in the Pacific Ocean, near Guerrero Negro, in Mexico's Baja California peninsula. (Photo by Dario Lopez-Mills/AP Photo)

1: Dubai's Burj Khalifa is the tallest building in the world, but perhaps not for long. Saudi Arabia has announced plans to build a 1 kilometer (3,280 foot) tower into the sky, to be named the Jeddah Tower, scheduled for completion in 2020. The Burj Khallifa currently stands at 2,716 ft. (Photo by Matthias Seifert/Reuters)

This combination of April 15, 2013 and April 2, 2014 photos show a police officer clearing Boylston Street following a bomb blast near the finish line of the 2013 Boston Marathon, and pedestrians crossing at the same corner nearly a year later in Boston. (Photo by Charles Krupa/AP Photo)

#1: Superman. According to McAfee, 16.50% of Web searches for Superman led to sites with viruses and other malicious software. Pictured here: The Superman costume that was worn by Christopher Reeve in “Superman: The Movie” on display at Profiles In History in Calabasas, northwest of downtown Los Angeles, on July 19, 2012 in California. (Photo by Frederic J. Brown/AFP Photo)

Max Verstappen of Netherlands and Red Bull Racing prepares to drive in the garage during practice for the F1 Grand Prix of Spain at Circuit de Barcelona-Catalunya on August 14, 2020 in Barcelona, Spain. (Photo by Mark Thompson/Getty Images)