An Afghan National Army (ANA) soldier assigned to the Mobile Strike Force Kandak fires a RPG-7 rocket-propelled grenade launcher during a live-fire exercise supervised by the Marines with the Mobile Strike Force Advisor Team on Camp Shorabak, Helmand province, Afghanistan, May 20, 2013. The Marines with the Mobile Strike Force Advisor Team instructed and mentored their ANA counterparts on how to properly utilize their weapons systems. (Photo by SSgt Ezekiel R. Kitandwe/RCT 7)

People walk past a sculpture entitled “Reunion” by artist Sam Jinks at a preview of the Melbourne Art Fair in Melbourne on August 1, 2018. The sculpture is made of silicone, pigment, resin and human hair. (Photo by William West/AFP Photo)

Retired 90 year old Frank Foss of St. Petersburg, Florida, with his home made banjo, made from a frying pan, a length of wood and some strings. (Photo by Fox Photos/Getty Images). 2nd July 1972

Revellers take part in the the 70th Annual Columbus Day Parade in New York, October 13, 2014. (Photo by Eduardo Munoz/Reuters)

Planes land in fog at Heathrow Airport, west London, as heavy fog covers a many parts of the south east, on April 1, 2014. (Photo by Steve Parsons/PA Wire)

A sun bear is offered chocolate by a visitor in its enclosure at a zoo in Bandung on January 18, 2017. Animal rights activists on January 18 demanded the closure of an Indonesian zoo after skeletal sun bears were pictured begging for food from visitors and eating their own dung. (Photo by Timur Matahari/AFP Photo)

Robot couple Xiaolan (L) and Xiaotao carry trays of food at a restaurant in Jinhua, Zhejiang province, China, May 18, 2015. The restaurant, which opened on Monday, has two robots delivering food for customers. The robots were designed as a couple, Xiaolan and Xiaotao, according to local media. (Photo by Reuters/Stringer)