School leavers celebrate their graduation in Moscow's Red Square in Moscow, Russia on June 20, 2019. (Photo by Artyom Geodakyan/TASS)

Matthias Broda, inventor and designer of the wooden e-bike, cycles a prototype along a street in Berlin, November 20, 2014. The wooden e-bike produced by German company Aceteam from ash wood, will be launched on the market by spring 2015 and will cost around 3,950 euro (4,950 dollars). The e-bike will be equipped with an 250W e-bike motor for a range of up to 100 kilometer (62 miles) with a rechargeable battery. (Photo by Fabrizio Bensch/Reuters)

Visitors gather outside Ark Encounter, a 100 million USD, 510-foot-long re-creation of Noah's Ark in Williamstown Kentucky, USA, 05 July 2016. Ark Encounter is the brainchild of Australian-born creationist Ken Ham; it was built with the help of state tax incentives and the sale of 62 million USD in junk bonds. (Photo by Jim Lo Scalzo/EPA)

Gentoo penguins begin the breeding season at Edinburgh Zoo on March 1, 2011 in Edinburgh, Scotland. The zoo keepers have just installed the nest rings in the penguin enclosure. The male penguins will then collect pebbles and offer them to the females to fill nest rings with, this helps keep the eggs and chick up off the ground and is part of their courtship display. (Photo by Jeff J Mitchell/Getty Images)ю EDINBURGH, SCOTLAND – MARCH 01

Models pose backstage at the Boy and Girl by Band of Outsiders Spring 2012 fashion show during Mercedes-Benz Fashion Week on September 10, 2011 in New York City. (Photo by Chelsea Lauren/Getty Images)

An inflatable pig flies above Battersea Power Station in a recreation of Pink Floyd's “Animals” album cover on September 26, 2011 in London, England. The classic Pink Floyd album artwork was recreated to mark the release of several digitally remastered versions of their albums. (Photo by Oli Scarff/Getty Images)

Members of Saudi security forces take part in a military parade in preparation for the annual Haj pilgrimage in the holy city of Mecca September 17, 2015. (Photo by Ahmad Masood/Reuters)

Members of the Indian Border Security Force (BSF) demonstrate their skills on motor-bikes during the BSF Golden Jubilee Day celebration in New Delhi on December 1, 2015. (Photo by Money Sharma/AFP Photo)