Paramilitary policemen take part in a training in Chaohu, Anhui province, China December 28, 2015. (Photo by Reuters/China Daily)

Megan McKenna, Amber Turner and Yazmin Oukhellou sightings at Aristocats nightclub Mayfair on March 30, 2017 in London, England. (Photo by Goff Photos)

An AH-64D Apache attack helicopter flies in front of a wall of fire during the South Carolina National Guard Air and Ground Expo at McEntire Joint National Guard Base, South Carolina, U.S. on May 6, 2017. (Photo by Jorge Intriago/Reuters/Courtesy Air National Guard)

An incredible clear-air lightning display from storms to the east of Noonamah, just outside Darwin on April 6, 2015. (Photo by Jacci Ingham/The Guardian)

“Slow”. A calm cow in the messy streets of Jodhpur. Photo location: India. (Photo and caption by Matthias Troeger/National Geographic Photo Contest)

Eugloss dilemma, male, Florida, Biscayne National Monument. (Photo and caption by Sam Droege/USGS Bee Inventory and Monitoring Lab)

A nesting bird peeks out of the budding Japanese Yoshino cherry tree along the Tidal Basin in Washington, Sunday, April 7, 2013. Despite repeated predictions peak blossom time for the historic cherry trees is not yet here, but almost, almost. (Photo by Carolyn Kaster/AP Photo)