A prototype battery-powered plane, called Greased Lightning or GL-10 is pictured flying at NASA's Langley Research Center in this undated handout photo obtained by Reuters May 1, 2015. The plane, which has 10 engines and can take off like a helicopter and fly efficiently like an aircraft, is currently in the design and testing phase. (Photo by Reuters/NASA)

A woman weeps after an announcement that Thailand's King Bhumibol Adulyadej has died, at the Siriraj hospital in Bangkok, Thailand, October 13, 2016. Thailand's Royal Palace says King Bhumibol, the world's longest-reigning monarch, has died at age 88. (Photo by Athit Perawongmetha/Reuters)

A Vietnamese bride is seen pushing the groom on a scooter during a photo shoot for their wedding in An Bang Beach outside Hoi An in Vietnam December 11, 2016. (Photo by Reuters/Stringer)

A customer asks for the price of a bittergourd at Duri market on a railway track in Jakarta, January 8, 2016. Indonesia's annual inflation rate cooled to the lowest in six years in December, which might pave the way for the central bank to cut a benchmark rate held at 7.50 percent since February 2015. (Photo by Reuters/Beawiharta)

A migrant tries to restrain her tent from strong winds in a makeshift camp for refugees and migrants at the Greek-Macedonian border near the village of Idomeni, Greece, March 24, 2016. (Photo by Alexandros Avramidis/Reuters)

Police officers display their AI-powered smart glasses in Luoyang, Henan province, China on April 4, 2018. (Photo by Reuters/China Stringer Network)

Revellers in Blackpool kept the bank holiday party going on May 30, 2018, taking full advantage of the warm weather and long weekend to let rip. The bank holiday booze up continued across Britain with one party-goer managing to accidentally flash her knickers in public. A bank holiday is a public holiday in the United Kingdom and some Commonwealth countries. (Photo by NB Press Ltd/The Sun)

A group of teachers and their student use makeshift raft as they cross the street during flood that hit Ranomeeto Barat village in Konawe Selatan, Sulawesi island, Indonesia, July 10, 2018. (Photo by Jojon/Reuters/Antara Foto)