Children play on an abandoned car near a protest, which is against the dissolution of Yemen's parliament and the Shi'ite Muslim Houthi militia's tightening grip on power, in the southwestern city of Taiz, February 13, 2015. (Photo by Mohamed al-Sayaghi/Reuters)

A white Bengal tiger cub plays with its mother in a zoo in the Siberian city of Novosibirsk, about 2,800 kilometers (1,750 miles) east of Moscow, Russia, Tuesday, April 21, 2015. Two blue-eyed Bengal tiger cubs were born in March to a couple of white tigers at Novosibirsk zoo. (Photo by Ilnar Salakhiev/AP Photo)

An armed man gestures in front of the police headquarters in Slaviansk, April 12, 2014. At least 20 armed militants wearing mismatched camouflage outfits took over the police and security services headquarters in the eastern city of Slaviansk seizing hundreds of handguns. (Photo by Gleb Garanich/Reuters)

Colleen Kelley, of Iowa City, Iowa, fixes the hat on her dog Bruce during judging at the 35th annual Drake Relays Beautiful Bulldog Contest, Monday, April 21, 2014, in Des Moines, Iowa. The pageant kicks off the Drake Relays festivities at Drake University where a bulldog is the mascot. (Photo by Charlie Neibergall/AP Photo)

The Öresund or Øresund Bridge is a double-track railway and dual carriageway bridge-tunnel across the Øresund strait between Scania (southernmost Sweden) and Denmark. The bridge runs nearly 8 km (5 miles) from the Swedish coast to the artificial island of Peberholm, which lies in the middle of the strait. The remainder of the link is by a 4 km (2.5 mile) tunnel from Peberholm to the Danish island of Amager. The Øresund Bridge is the longest combined road and rail bridge in Europe, and connects two major metropolitan areas: Copenhagen, the Danish capital city, and the major Swedish city of Malmö. It connects the road and rail networks of Scandinavia with those of Central and Western Europe.

Sam Warren climbs in to a prototype combat vehicle during the PrepperCon expo Friday, April 24, 2015, in Sandy, Utah. Hundreds of survivalists and “preppers” are gathering in the Salt Lake City suburb of Sandy for the first annual PrepperCon, featuring demonstrations of underground bunkers, food storage, and armored vehicles. (Photo by Rick Bowmer/AP Photo)

In this Friday, December 5, 2014 photo, Iranian volunteer Asal Moghaddam plays with dogs at the Vafa Animal Shelter in the city of Hashtgerd 43 miles (73 kilometers) west of the capital Tehran, Iran. More than 500 dogs find care and affection at the Vafa Animal Shelter, which was established through an endowment in 2004 and is the country’s only licensed animal refuge. (Photo by Vahid Salemi/AP Photo)

Clowns take part in the annual pilgrimage to the Basilica of Our Lady Guadalupe to pay homage to the Virgin of Guadalupe in Mexico City December 16, 2014. Dressed in colourful costumes, hundreds of clowns from all over Mexico walked towards the Basilica to give thanks to the virgin for the work they have received. (Photo by Carlos Jasso/Reuters)