Shipping containers sit idle at the ports of Los Angeles and Long Beach, California in this aerial photo taken February 6, 2015. The loading and unloading of cargo freighters has been suspended at all 29 U.S. West Coast ports this weekend because of chronic slowdowns on the docks that shippers and terminal operators have blamed on the dockworkers' union, the companies said Friday. (Photo by Bob Riha, Jr./Reuters)

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)

Bjorn, aged 5, smiles as he poses with a Owl butterfly during an event to launch the Sensational Butterflies exhibition at the Natural History Museum in London, Britain March 23, 2016. The exhibition opens to the public on March 24 and runs until September 11. (Photo by Dylan Martinez/Reuters)

A picture made available on 09 October 2016 shows competitors during a Legion Run event, in Sofiko near the city of Corinth, Greece, 08 October 2016. Legion Run is run covering five kilometres with obstacles of mud, fire, ice and barbed wire, which takes place in different countries around the globe. (Photo by Vassilis Psomas/EPA)

Rita Ora strips down to promote the new Tezenis lingerie range on December 7, 2016. The British singer, 26, shows off her curves in the latest campaign for the Italian brand. (Photo by Splash News/Tezenis)

A giant size figure of the United States' goalkeeper Tim Howard is displayed outside a shopping mall in Hong Kong, Thursday, June 12, 2014, to promote the upcoming 2014 World Cup in Brazil. A total of seven 3.5 meters to 4 meters (11 feet 6 inch to 13 feet one inch) tall figures of famous players attract many soccer fans. (Photo by Vincent Yu/AP Photo)

Bob Steele, of Jefferson, Texas, positions his bears during The Great Bear Show at the Dubuque (Iowa) County Fair on July 25, 2012. (Photo by Jessica Reilly/Telegraph Herald)