An Amur tiger walks across a passageway after a news conference at the Philadelphia Zoo, Wednesday, May 7, 2014, in Philadelphia. The see-through mesh pathway called Big Cat Crossing is part of a national trend called animal rotation that zoos use to enrich the experience of both creatures and guests. (Photo by Matt Slocum/AP Photo)

A replica model of a Lamborghini Aventador LP 700-4 in Dubai, UAE. This is the world's most expensive model car, made from carbon fibre and covered in a thin layer of pure gold. The 1:8 scale replica Lamborghini Aventador LP 700-4, designed by German engineer Robert Gülpen, is available to buy for £200,000. But amazingly this model – currently on display at the Lamborghini showroom in Dubai – is just a prototype for a solid gold model, which will go up for auction in 2014 with a price tag of £4.6 million. (Photo by Robert Gulpen/Barcroft Media)

Labourers who work nearby nap on a road as cars drive past in Chongqing Municipality, July 23, 2013. (Photo by Reuters/Stringer)

“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)

A vehicle lies on a road in Adairsville. (Photo by David Goldman/Associated Press)

A ring-tailed lemur is pictured at Zoom Torino, a zoological park in Cumiana near Turin, on April 22, 2015. Zoom Torino is a new immersive zoological park, where animals can be seen without bars or cages, only natural barriers ensure the visit. (Photo by Marco Bertorello/AFP Photo)

A bride from the Santa Marta slum takes a break after getting her makeup done before a group wedding in Rio de Janeiro December 17, 2014. A total of 16 couples took part in a mass wedding ceremony organized by the Police Peacekeeping Unit (UPP) as part of activities geared towards social enhancement of the slums. (Photo by Pilar Olivares/Reuters)

“Kim Jong-il, also written as Kim Jong Il, birth name Yuri Irsenovich Kim (according to Soviet records) (16 February 1941/2 – 17 December 2011), was the supreme Leader of the Democratic People's Republic of Korea (North Korea). He was the General Secretary of the Workers' Party of Korea, the ruling party since 1948, Chairman of the the National Defence Commission of North Korea, and the Supreme Commander of the Korean People's Army, the fourth-largest standing army in the world”. – Wikipedia

Photo: North Korean leader Kim Jong Il inspects a military unit in North Korea. (Photo by Korean Central Television/Yonhap)