Li Yuming, a local farmer who is interested in scientific invention, works on his unfinished miniature submarine “Xiaguang V” on the outskirts of Wuhan, capital of central China's Hubei province August 24, 2007. “Xiaguang V”, which is 3-metre long, 1.2-metre in height, has a maximum diving depth of 20 metres, and can hold two adults and one child at the same time. The submarine will be used for tour after safety test, local media said. (Photo by Reuters/Stringer)

This photo released by North Korea's official Korean Central News Agency (KCNA) on June 7, 2012 shows North Korean leader Kim Jong-Un (C) surrounded by members of the Korean Children's Union (KCU) organizations during a joint national meeting to celebrate the 66th anniversary of the KCU organizations at Kim Il-Sung Stadium in Pyongyang on June 6, 2012. (Photo by AFP Photo/KCNA via KNS)

Yalena Leuliette, 7, of Greenbelt, Md., throws seeds from a cattail plant up in the air as she plays while visiting the Kenilworth Aquatic Gardens in northeast Washington, on Sunday, August 9, 2015. Leuliette visits the public garden with her parents a few times a year. (Photo by Jacquelyn Martin/AP Photo)

“The Curiosity Mars rover has imaged a small metallic-looking protuberance on a rock. Visible (in the image below the green lines point to it), the protuberance appears to have a high albedo and even projects a shadow on the rock below...”

A group of 1000 customers receive a facial massage at a sports centre in Jinan, Shandong province, China, May 4, 2015. A group of 1000 women were given a 30 minutes facial beauty treatment together on Monday that achieved a Guinness record for the largest group of people having beauty treatment in the same location, according to local media. (Photo by Reuters/Stringer)

A picture taken on October 17, 2014 in Vevey shows a giant fork designed by Switzerland's artist Jean-Pierre Zaugg to commemorate Nestle's Alimentarium Food Museum 10th anniversary. World's biggest food company, Swiss Nestle Group announced results sales down by 3.1% for the first nine months of 2014 to 66.2 billion Swiss francs (55.1 billion euros). (Photo by Fabrice Coffrini/AFP Photo)

Cheerleaders let their hair fly as they perform prior to a German first division Bundesliga soccer match between 1. FC Cologne and Bayern Munich in Cologne, Germany, March 4, 2017. (Photo by Michael Probst/AP Photo)

This file photo provided on Sunday February 15, 2015 by the Syrian anti-government activist group Aleppo Media Center (AMC), which has been authenticated based on its contents and other AP reporting, shows Syrian rebels firing locally made shells against the Syrian government forces, in Aleppo, Syria. (Photo by AP Photo/Aleppo Media Center)