A group of youngsters dressed as ghouls and zombies for Halloween parade in downtown Lisbon, Portugal, Friday, October 31, 2014. (Photo by Francisco Seco/AP Photo)

A tourist poses for a picture with the Sphinx at the Pyramids of Giza in Cairo, Egypt, on October 19, 2011. (Reuters/Jamal Saidi)

In this November 28, 1966 file photo, one of the 10 beagles involved in the first test of the Veterans Administration Hospital in East Orange, N.J. smokes a cigarette through a machine linked to its windpipe by a plastic tube to test any link between smoking and emphysema. (Photo by AP Photo)

Photographers take photographs of the Large Air Tanker (LAT) C-130 Hercules, also known as “Thor”, as it drops a load of around 15,000 litres during a display by the Rural Fire Service ahead of the bushfire season at RAAF Base Richmond Sydney, Australia, September 1, 2017. (Photo by David Gray/Reuters)

An Indonesian vendor fixes a headscarf on a mannequin at a market in Jakarta in this December 21, 2006 file photo. (Photo by Reuters/Beawiharta)

A niqab-wearing Salafist protester takes a selfie as she attends a demonstration against the ban on the sale and manufacturing of the full-burqa in Rabat January 15, 2017. (Photo by Reuters/Stringer)

Winner. “I took this vertical image in the Quarry Bay district of Hong Kong during the dusk ‘blue hour’, when there was a perfect balance between the ambient light in the sky and the artificial lights of the high-rise residential buildings”. (Photo by Jatinder Heer/The Guardian)