Planes land in fog at Heathrow Airport, west London, as heavy fog covers a many parts of the south east, on April 1, 2014. (Photo by Steve Parsons/PA Wire)

Palestinian female Hamas security officers demonstrate their skills during a graduation ceremony in the northern Gaza Strip, Wednesday, April 2, 2014. 1200 officers graduated from advanced training courses that lasted one year in Gaza police academy of Hamas. (Photo by Adel Hana/AP Photo)

Riot police face off with demonstrators at the “Occupy Denver” camp on October 29, 2011 in Denver, Colorado. Following a march by protesters, police moved in on their encampment to tear down recently erected tents. They arrested numerous protesters, pepper-sprayed others and others reportedly fired rubber bullets at the crowd during the confrontation. (Photo by John Moore/Getty Images)

Kalei Ferrin,3, holds a sign up in support of gay rights during the San Diego gay pride parade July 16, 2011 in San Diego, California. About 200 active-duty troops and veterans from every branch of the military participated for the first time in the march as the ban on the government policy on homosexuals serving in armed forces, or “Don't ask Don't Tell”, remains in flux in the justice system. (Photo by Sandy Huffaker/Getty Images)

A picture taken on March 16, 2017 shows women dressed up as mermaids posing by a pool at a mermaid training school in Moscow. Russian women who have dreamt of becoming a mermaid since their youngest years, start turning their fantasies into reality with a new type of fitness – mermaid swimming. (Photo by Natalia Kolesnikova/AFP Photo)

Young Japanese women pose with a green bear costumed person during the 'Earth Parade 2015' in Tokyo, Japan, Saturday, November 28, 2015. Ahead of the U.N. climate change summit in Paris starting this week, about 1,000 citizens and environmental activists took to the streets of Tokyo on Saturday, calling for strong actions to combat global warming. (Photo by Franck Robichon/EPA)

A fox runs out onto the pitch before the start of the second half. Celtic League 2012/13, Round 19, Leinster v Ulster, RDS, Ballsbridge, Dublin, March 30, 2013. (Photo by Paul Mohan)

A racegoer uses the camera on her phone to check her hair on the opening day of the Grand National Festival at Aintree Racecourse on April 3, 2014 in Aintree, England. The three days of racing attracts thousands of racegoers and fans from across the world. The meeting culminates with millions of pounds being wagered on the runners taking part in Europe's richest jump race, the Grand National. (Photo by Christopher Furlong/Getty Images)