Racegoers in fashionable hats attend Ladies Day at Cheltenham Festival on March 15, 2017 in Cheltenham, England. (Photo by David Davies/PA Wire)

Monks take a tiger out of its cage for an afternoon walk June 5, 2001 at the Wat Pa Luangta Bua monastery in Kanchanaburi, Thailand. (Photo by Paula Bronstein/Getty Images)

A general view of the sunrise over Hawes, Wensleydale, UK on November 24, 2014. (Photo by Neil Squires/PA Wire)

A woman struggles with an umbrella in the wind and rain while walking in Derby city centre, on December 23, 2013. (Photo by Rui Vieira/PA Wire)

A dog walker on Longsands beach before sunrise in Tynemouth, UK on April 1, 2016. (Photo by Owen Humphreys/PA Wire)

Submersible “Jiaolong” is put into the sea for the second dive during a series of six scheduled ones to attempt the country's deepest-ever 7,000-meter manned dive on June 19, 2012 in At Sea, Unspecified. The submersible “Jiaolong”, carrying three people, reportedly reached a depth of 6,965 meters in the Mariana Trench, the deepest part of the world's oceans which is located in the western Pacific Ocean, on June 19, local time. (Photo by China Foto Press)

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)