Tourist Police sit in the shade on a road leading to the Coptic Cairo area on May 27, 2011 in Cairo, Egypt. Protests in January and February brought an end to 30 years of autocratic rule by President Hosni Mubarak who will now face trial. Food prices have doubled and youth unemployment stands at 30%. Tourism is yet to return to pre-uprising levels. (Photo by Peter Macdiarmid/Getty Images)

A new monorail service in Houston, Texas, ready for its inaugural service. (Photo by Evans/Three Lions/Getty Images). Circa 1950

Selena Gomez performs at the MTV Movie Awards. (Photo by Jordan Strauss/Invision for MTV)

Sleeping Anthidium. Female Anthidium punctatum; Size: 7 mm. (Photo by John Hallmén)

A worker looks at an old soviet tank T-34 (L) as he fixes military vehicle (R) at a Phaeton museum in Zaporizhia, Ukraine, August 11, 2015. The museum stopped the restoration works of their collection of about 120 retro autos and motorcycles to help the Ukrainian army to restore military vehicles and equipment which will be used in the conflict in Ukraine eastern regions. (Photo by Gleb Garanich/Reuters)

A performer dressed in costume prepares to participate in the Gay and Lesbian Mardi Gras parade in Sydney, Australia, March 5, 2016. The Sydney Mardi Gras parade began in 1978 as a march and commemoration of the 1969 Stonewall Riots of New York. It is an annual event promoting awareness of gay, lesbian, bisexual and transgender issues and themes. (Photo by David Gray/Reuters)

A newly born Indian white tiger cub yawns in its enclosure at Liberec Zoo, Czech Republic, April 25, 2016. (Photo by David W. Cerny/Reuters)