A pig's head is seen in a basin after it was slaughtered it in the village of Azerany, Belarus, December 12, 2015. (Photo by Vasily Fedosenko/Reuters)

Damaged buildings are pictured at night in Aleppo, Syria December 11, 2015. (Photo by Ammar Abdullah/Reuters)

Passengers travel on the London train and underground system during the Christmas party season, December 18, 2015. (Photo by Paul Hackett/Reuters)

People take photos with the skyline of the central business district in Singapore on September 10, 2015. (Photo by Edgar Su/Reuters)

Turkish artist Nezaket Ekici performs a live art performance entitled 'Emotion in Motion' on the first day of Art Basel 2015, Hong Kong, China, 13 March 2015. The Hong Kong show of Art Basel features 233 galleries from 37 countries and territories, presenting works ranging from the Modern period of the early 20th century to the most contemporary artists of today, according to the official press release. (Photo by Alex Hofford/EPA)

A volcanic eruption at Mount Etna’s Vorgaine crater in Sicily, Italy on December 3, 2015. (Photo by Marco Restivo/Barcroft Media)

A farmer rides a truck in a village near Nong Khai, Thailand, September 16, 2015. (Photo by Jorge Silva/Reuters)

An Iraqi army cadet performs “the leap of faith” from a bridge in Baghdad, September 22, 2015. (Photo by Ahmed Saad/Reuters)