A sewer cleaner of Dhaka City Corporation cleaning out the city's sewers on May 03, 2017 in Dhaka, Bangladesh. Despite a rise in the number of deaths of manhole workers every year, workers regularly go into the manholes without any protective gear. (Photo by Zakir Chowdhury/Barcroft Images)

US actress Alexandra Daddario attends the “Baywatch” Photo Call in Berlin on May 30, 2017 in Berlin, Germany. (Photo by Splash News and Pictures)

A lemur licks a block of ice containing fruit at Rome's Bioparco zoo, Wednesday, July 5, 2017. Zookeepers at the Bioparco often give animals ice blocks with either fruit or meat on hot summer days. (Photo by Gregorio Borgia/AP Photo)

The supermoon rises behind Glastonbury Tor on September 27, 2015 in Glastonbury, England. Tonight's supermoon, so called because it is the closet full moon to the Earth this year, is particularly rare as it coincides with a lunar eclipse, a combination that has not happened since 1982 and won't happen again until 2033. (Photo by Matt Cardy/Getty Images)

A man flies a kite on the Bund while buildings of Pudong's Lujiazui financial district stand across the Huangpu River as the sun rises in Shanghai, China, on Friday, October 2, 2015. (Photo by Qilai Shen/Bloomberg)

Singer Rihanna prepares for a photoshoot with photographer Annie Leibovitz in Havana, Cuba, May 28, 2015. (Photo by Reuters/Stringer)

“The Boeing X-45 unmanned combat air vehicle is a concept demonstrator for a next generation of completely autonomous military aircraft, developed by Boeing's Phantom Works. Manufactured by Boeing Integrated Defense Systems, the X-45 was a part of DARPA's J-UCAS project”. – Wikipedia

Photo: Two X-45A Unmanned Combat Air Vehicles (UCAV) are shown to members of the news media July 11, 2002 at Edwards Air Force Base, California. The X-45A, developed by The Defense Advanced Research Projects Agency and the Boeing Company, is the first unmanned system designed from inception for combat missions. (Photo by David McNew/Getty Images)

Thousands of revelers continue to enjoy themselves throughout the night on Sunrise Beach on February 25, 2005 in Haadrian, Koh Phangan. (Photo by Shaul Schwarz/Getty Images)