Military vehicles surround a wreckage of a trolleybus, in Volgograd, Russia, Monday, December 30, 2013. A bomb blast tore through a trolleybus in the city of Volgograd on Monday morning, killing at least 10 people a day after a suicide bombing that killed at least 17 at the city's main railway station. Volgograd is about 650 kilometers (400 miles) northeast of Sochi, where the Olympics are to be held. (Photo by Denis Tyrin/AP Photo)

Israeli soldiers get ready to launch the Skylark drone during a drill on January 16, 2012 near Bat Shlomo, Israel. (Photo by Uriel Sinai/Getty Images)

In this Thursday, October 3, 2019 photo, a female black bear sleeps with its tongue out high up in a Ponderosa pine tree near Clark Fork School in the Rattlesnake neighborhood of Missoula, Mont. The bear's cub, not pictured, was snoozing on a nearby branch. (Photo by Tommy Martino/The Missoulian via AP Photo)

Located at the foot of the Rocky Mountains on the North Saskatchewan River, the rare phenomenon occurs each winter in the man-made lake. Photo: Ice bubbles in Abraham Lake. (Photo by Chip Phillips/Rex Features)

The sea leopard. The Antarctic Peninsula. (Photo by Paul Nicklen)

Artist Matthew Albanese creates amazing miniature landscapes made from sugar, chocolate and even bits of ostrich in his living room. All the models were painstakingly recreated in his living room, which he uses as his studio. Each gruelling piece can take up to as many as 700 hours to complete. Photo: A stormy version of “New Life 2” created by Matthew Albanese. (Photo by Matthew Albanese/Barcroft Media)

A Salvadorean clown going by the name of “Almohadita” poses during National Clown Day celebrations at Beethoven Square in San Salvador December 3, 2014. The Salvadorean congress declared the second Wednesday of December as National Clown Day to honour all Salvadorean clowns in their efforts to bring fun to the country, reported local media. (Photo by Jose Cabezas/Reuters)