A member of the Eton public school O.T.C. (Officers Training Corps) practising shouting out orders during a training session, 20th January 1940. (Photo by Hulton Archive/Getty Images)

Indian soldiers practice their stunts on Royal Enfield motorcycles in preparation for the upcoming Republic Day parade on January 11, 2012 in New Delhi, India. (Photo by Daniel Berehulak /Getty Images)

A potential bidder carefully examines pieces of Tuna in order to ascertain the quality and to estimate its price ahead of the Tuna auction at the Tsukiji fish market on February 28, 2012 in Tokyo, Japan. (Photo by Daniel Berehulak /Getty Images)

Moscow riot police prepare to move on activists during an unsacnctioned anti-Putin opposition rally at the Pushkin Square March 5, 2012 in central Moscow, Russia. Amid charges of fraud, demonstrators took to the streets a day after Vladimir Putin declared victory in Russia's presidential elections. (Photos by: Rustem Adagamov; Source: LiveJournal; Gleb Shchelkunov; Source: LiveJournal; Ilya Varlamov; Source: LiveJournal; Raskalov; Source: LiveJournal; Dmitry Chistoprudov; Source: LiveJournal)

A dog and its owner perform a routine in the main arena on Day three of Crufts at the Birmingham NEC Arena on March 10, 2012 in Birmingham, England. (Photo by Dan Kitwood/Getty Images)

Irwan bathes a domesticated crocodile at his house in Bogor, Indonesia on January 22, 2018. Irwan found it as a baby and now it has been living with Irwans family for 20 years. Indonesia is known as a hotbed of exotic pet domestication and trade. People have been known to keep endangered animals such as slow lorises, eagles and pangolins, angering conservationists and animal rights activists. (Photo by Eko Siswono Toyudho/Anadolu Agency/Getty Images)

“The scientists behind NASA's $2.5 billion Curiosity rover mission on Mars on Tuesday explained the nature of a tiny, gleaming "flower" embedded in Red Planet rock, and revealed where they'll be using the SUV-sized robot's drill for the first time”. – Alan Boyle via NBCNews.com

Photo: Scientists say that a “Martian flower”, seen here in an image from the Curiosity rover's Mars Hand Lens Imager, is a 2-millimeter-wide grain or pebble that's embedded in the surrounding rock. Another, darker-colored mineral grain can be seen above and to the left. (Photo by NASA)

Maria, 18, wearing a traditional Sevillana outfit, poses for a portrait during the traditional Feria de Abril (April fair) in the Andalusian capital of Seville April 16, 2013. (Photo by Marcelo del Pozo/Reuters)