RAF Tornados fly above the Lossiemouth air base on March 18, 2011 in Lossiemouth, Scotland. UK defence forces will help to enforce a no-fly zone over Libya after the UN voted in favour of a resolution that backed 'all necessary measures', except a foreign occupation force, to protect Libyan civilians.

In this handout image provided by the City of New York, a Nissan NV200 is seen as a New York City taxi cab in New York City. The Taxi and Limousine Commission along with New York City Mayor Michael Bloomberg announced the Nissan NV200 designed by Nissan North America, Inc., has been chosen as the winner of the Taxi of Tomorrow competition and will become the City's exclusive taxicab for a decade. (Photo by City of New York via Getty Images)

Mr. Ben, a pygmy slow loris, is administed anesthetic during one of Bristol Zoo's in-house veterinary clinic routine health check-up and teeth clean as part of the Zoo's standard animal husbandry and welfare procedure at Bristol Zoo on June 18, 2009 in Bristol, England. (Photo by Matt Cardy/Getty Images)

Protester Nadine Wolf demonstrates against the proposed Stop Online Piracy Act (SOPA) and Protect IP Act (PIPA) outside the offices of U.S. Sen. Charles Schumer (D-NY) and U.S. Sen. Kirsten Gillibrand (D-NY) on January 18, 2012 in New York City. (Photo by Mario Tama/Getty Images)

Sister Milly Wu (16) and Chloe Wu (18), both students from Manchester pose for photographs at the Hyper Japan 2012 Event at the Earls Court Exhibition Centre on February 24, 2012 in London, England. (Photo by Matthew Lloyd/Getty Images)

Participants dance and climb on an art installation as approximately 70,000 people from all over the world gather for the 30th annual Burning Man arts and music festival in the Black Rock Desert of Nevada, U.S. August 31, 2016. (Photo by Jim Urquhart/Reuters)

People take cover outside the Fort Lauderdale-Hollywood International airport after a shooting took place near the baggage claim on January 6, 2017 in Fort Lauderdale, Florida. Officials are reporting that five people were killed and 8 wounded in an attack by a single gunman. (Photo by Joe Raedle/Getty Images)

Dancers of the Czech National Ballet warm up backstage during a performance of “The Nutcracker – A Christmas Carol” at the National Theatre in Prague, Czech Republic, late 16 December 2017. Peter I. Tchaikovsky's “The Nutcracker”, one of his most famous compositions and seasonal ballets, premiered in St. Petersburg, Russia, on 18 December 1872, celebrates its 125th anniversary this year. (Photo by Martin Divisek/EPA/EFE)