Professional dog walker Jon Lovette of Jonny Walkers walks with dogs at Crissy Field on October 19, 2011 in San Francisco, California.

A group of Ring Tailed Lemurs eat from a Thanksgiving spread at the San Francisco Zoo on November 23, 2011 in San Francisco, California. Fifteen lemurs at the San Francisco Zoo were treated to a Thanksgiving feast of green beans, a fruit salad made up of apples, bananas, grapes sweet potatoes and a turkey made out of monkey chow. (Photo by Justin Sullivan/Getty Images)

This aerial photo shows the wreckage of the Asiana Flight 214 airplane after it crashed at the San Francisco International Airport in San Francisco, Saturday, July 6, 2013. (Photo by Marcio Jose Sanchez/AP Photo)

Apple Senior VP of Worldwide Marketing Phil Schiller talks about the display on the new iPad during an Apple product launch event at Yerba Buena Center for the Arts on March 7, 2012 in San Francisco, California. In the first product release following the death of Steve Jobs, Apple Inc. introduced the third version of the iPad (iOS 5.1; Processor is an Apple A5X ARM-based unit; Display 2048 x 1536 pixels; Camera is set at 5 megapixels and has a 5-element lens plus auto face-detection, auto focus lock and image stabilisation for video; Wi-Fi + 4G) and an updated Apple TV. (Photo by Kevork Djansezian/Getty Images)

Suspension artist and LUSH Cosmetics employee Alice Newstead inspects shark hooks that she had pierced into her skin during a demonstration against the shark fin trade at a LUSH Cosmetic store on August 24, 2011 in San Francisco, California.

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.

A Kurdish female fighter from the People's Protection Units (YPG) gestures as she carries her weapon near al-Hawl area where fighting between Islamic State fighters and fighters from Democratic Forces of Syria are taking place in south-eastern city of Hasaka, Syria November 10, 2015. (Photo by Rodi Said/Reuters)