Tree trunks and rocks are set up to support a leaning wall of Li Yonghua's damaged cave house in an area where land is sinking next to a coal mine, in Helin village of Xiaoyi, China's Shanxi province, August 2, 2016. (Photo by Jason Lee/Reuters)

A female forest guard carries a tranquillizer gun in the Gir National Park and Wildlife Sanctuary in Sasan, in Gujarat December 2, 2014. The sanctuary, which is home to Asiatic lions in India, has an area of 1,412 sq km in which female guards were employed for the first time in India in 2007. The guards fetch a monthly salary of around $148 for working almost 12 hours a day, six days a week, said one of the female guards. (Photo by Anindito Mukherjee/Reuters)

Amateur contestants (L-R) Phil Bailey, John Hindle and Eren Emir pose in telephone booths during the annual European Elvis Tribute Artist Contest and Convention in Birmingham, central England January 2, 2015. (Photo by Darren Staples/Reuters)

A visitor kneels down nex to an iCub robot made by the Italian Institute of Technology at the scientists congress IROS 2015 in Hamburg, Germany October 2, 2015. The robot congress is organized by TAMS group (Technical Aspects of Multimodal Systems) of Hamburg's university. (Photo by Fabian Bimmer/Reuters)

Children wearing uniforms hold toy guns during a military parade game on China's National Day, at Beyou World, a centre children where can experience different kinds of professions, in Beijing, October 1, 2015. (Photo by Reuters/Stringer)

Models present Victoria Secret Fantasy Bras priced at $2 million each during a media preview of the Singapore JewelFest in Singapore October 8, 2015. The festival which is in its 13th year, sees over 42 Asian designers participating and over $300 million worth of jewels for sale. It opens from October 9 to 18. (Photo by Edgar Su/Reuters)

People attend a Halloween event at Ocean Park on October 30, 2015 in Hong Kong. Halloween – a named taken from 'All Hallows' Even' falls on the day before All Saints' Day on November 1 – a holiday when Christians remember their deceased loved ones. (Photo by Anthony Kwan/Getty Images)

People participate in a pillow fight to mark International Pillow Fight Day in the Heroes' Square, in central Budapest, Hungary, Saturday, April 2, 2016. The Pillow Fight Day attracts tens of thousands people in more than 100 cities all over the World each year. ((Photo by Zoltan Balogh/MTI via AP Photo)