A man poses in front of a portrait of late Chinese Chairman Mao Zedong during the opening of an exhibition of Mao related art in Beijing, China, September 8, 2016. (Photo by Thomas Peter/Reuters)

Labrador puppies “Hoey” (L) and “Hatton”, named in honor of September 11, 2001 attack victims Patrick Hoey and Lenny Hatton who died in the World Trade Center, are pictured on the grounds of the Pentagon near Washington, June 28, 2011. (Photo by Jason Reed/Reuters)

A person viewing the Northern lights over the lava landscape, Reykjanes Peninsula, Iceland. (Photo by Arctic-Images/Getty Images)

A navy diver storms into the gallery during a military display at Singapore's 52nd National Day celebrations at Marina Bay in Singapore August 9, 2017. (Photo by Edgar Su/Reuters)

Firefighters pull a pig as they try to rescue it from a well at a pig farm in Huanghua township of Leqing, Zhejiang province, China, April 25, 2014. Seven local firefighters successfully rescued the 300 kg (661 lbs) pig, local media reported. (Photo by Reuters/China Daily)

The sunken ferry Sewol sits on a semi-submersible ship during its salvage operations at the sea off Jindo, South Korea, in this handout picture provided by the Ministry of Oceans and Fisheries and released by Yonhap on March 26, 2017. (Photo by Reuters/Yonhap/The Ministry of Oceans and Fisheries)

Bikini Contest in Daytona Beach, Florida, USA. (Photo by Evan Hurd/Sygma/Sygma via Getty Images)

U.S Army combat camera photographer Spc. Hilda Clayton took this photo July 2, 2013 that was released by the U.S. Army, that shows an Afghan soldier engulfed in flame as a mortar tube explodes during an Afghan National Army live-fire training exercise in Laghman Province, Afghanistan. The accident killed Clayton and four Afghan National Army soldiers. (Photo by Spc. Hilda Clayton/U.S. Army via AP Photo)