Lilly Caron, 8, of Bridgeton, Maine, Jason Homchick, of San Diego, and Lilly's father Jason Caron, (obscured), ride the Sky Swing at Seacoast Adventure, Thursday, July 14, 2016, in Wyndham, Maine. The 100-foot-tall swing gives riders the combined thrills of sky diving and hang gliding. (Photo by Robert F. Bukaty/AP Photo)

A student falls asleep as she holds a book containing a portrait of China's late chairman Mao Zedong during a lesson at the Democracy Elementary and Middle School in Sitong town, Henan province December 3, 2013. In a remote part of central China, the day starts at the Democracy Elementary and Middle School with a pre-dawn jog, some revolutionary songs and then an activity long since forgotten at other schools: reciting quotations from Mao Zedong's famed “Little Red Book”. While the ruling Communist Party that Mao led continues to hold him in esteem as the leader of the Communist Revolution, his radical policies and teachings have been largely shelved since his death in 1976 in favour of a pro-market approach that has turned China from a backwater into the world's second biggest economy. The 120th anniversary of Mao's birth is on December 26, 2013. (Photo by Carlos Barria/Reuters)

“A balancing rock, also called balanced rock or precarious boulder, is a naturally occurring geological formation featuring a large rock or boulder, sometimes of substantial size, resting on other rocks, bedrock or on glacial till. Some formations known by this name only appear to be balancing but are in fact firmly connected to a base rock by a pedestal or stem”. – Wikipedia

Photo: “The Brimham Rocks are balancing rock formations located on Brimham Moor in North Yorkshire, England. The rocks stand at a height of nearly 30 metres in an area owned by the National Trust which is part of the Nidderdale Area of Outstanding Natural Beauty”. – Wikipedia. (Photo by Tee Time Tony)

Seized plastic handguns which were created using 3D printing technology are displayed at Kanagawa police station in Yokohama, south of Tokyo, in this photo taken by Kyodo May 8, 2014. Yoshimoto Imura became the first man to be arrested in Japan for illegal possession of two guns he created himself using 3D printing technology, Japanese media said on Thursday. The 27-year-old, a college employee in the city of Kawasaki, was arrested after police found video online posted by Imura claiming to have produced his own guns. Gun possession is strictly regulated in Japan. Police raided Imura's home and found five guns, two of which could fire real bullets, Japanese media said. (Photo by Reuters/Kyodo)

The new curvy Barbie doll body shape (L) is seen next to the traditional Barbie in a combination of photos released by Mattel on January 28, 2016. Barbie, the world's most famous doll, has a new body. In fact, she has three new bodies – petite, tall and curvy. Some 57 years after the impossibly busty and narrow-waisted blue-eyed Barbie doll was first introduced, California-based toy maker Mattel on Thursday released the new models, which it says better reflect a changing world. (Photo by Reuters/Mattel)

Demonstrators perform a dance in front of riot policemen during a march called by students to request changes in the education system in Santiago, Chile September 5, 2017. (Photo by Ivan Alvarado/Reuters)

A woman gets a pedicure in Port-au-Prince, Haiti, on October 13, 2017. (Photo by Andres Martinez Casares/AP Photo)

A lioness drinks after being fed by senior keeper Glynn Hennessy at ZSL London Zoo on August 10, 2016 in London, England. Today marks World Lion Day which highlights the first global campaign to celebrate the importance and plight of lions worldwide. (Photo by Carl Court/Getty Images)