Indian Air Force soldiers toss their rifles as they perform during the full-dress rehearsal for Indian Air Force Day at the Hindon air force station on the outskirts of New Delhi October 6, 2015. (Photo by Anindito Mukherjee/Reuters)

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 model wears a floral head dress as she promotes a chain of garden centres at the Royal Horticultural Soceity's Chelsea Flower Show in London, Britain, May 18, 2015. (Photo by Toby Melville/Reuters)

Taking it all in at Trolltunga, a piece of rock which juts horizontally out of a mountain, 700 metres above lake Ringedalsvatnet in Norway. (Photo by Sam Rogers/GuardianWitness)

US President Donald Trump' s daughter and senior White House adviser Ivanka Trump (2nd R) poses for a photo on a balcony of the VIP tent at the Olympic sliding centre with US army luge athletes Taylor Morris (L) and Matt Mortensen (2nd L), and US women’s bobsleigh silver medallist Lauren Gibbs (R) before the ski jump tower at the men' s four- man bobsleigh event of the Pyeongchang Winter Olympic games in Pyeongchang on February 25, 2018. (Photo by Eric Gaillard/Reuters)

Phuket, Thailand. The girl is in the pool, which is higher than the land, and the elephant is on the land behind the pool. The photographer used an underwater bag to get a half submerged image. (Photo by Justin Mott)

Greyhounds with stuffed and sprung model monkeys strapped to their backs before a hurdle race at Wellinborough. (Photo by E. Bacon). 21st April 1928

Mangli Munda poses on her wedding day with a stray dog in Jharkhand, India on August 30, 2014. An 18-year-old Indian girl has married a stray dog as a part of a tribal ritual designed to ward off an evil spell. Village elders hastily organised the wedding between Mangli Munda and the canine as the teenager is believed to be bringing bad luck to her community in a remote village in Jharkhand state. Mangli's father Sri Amnmunda agreed and even found a stray dog named Sheru as a match for his daughter. And while Mangli was a hesitant bride, she believes that the ceremony will help ensure that her future human husband will have a long life. (Photo by Barcroft Media/ABACAPress)