A pro-Russian rebel guards a captured former Ukrainian Army checkpoint outside Vuhlehirsk, Donetsk region, eastern Ukraine, Thursday, February 5, 2015. The rebels have closed in around the town in a strategy they triumphantly refer to as the Debaltseve cauldron. Separatists recently burst through government lines in the rural settlement of Vuhlehirsk. (Photo by Vadim Braydov/AP Photo)

People wearing Christmas hats bath in a pool of watermelon peel during a Christmas service at a hot spring in Luoyang, Henan province, China, December 24, 2016. (Photo by Reuters/Stringer)

A man takes a picture of sea spray as storms hit Cape Town, South Africa, June 7, 2017. (Photo by Mike Hutchings/Reuters)

A zoo performer smiles as he puts his head between the jaws of a crocodile during a performance for tourists at the Sriracha Tiger Zoo, in Chonburi province, east of Bangkok,Thailand, June 7, 2016. (Photo by Chaiwat Subprasom/Reuters)

A Hindu priest waits to perform prayers next to Tejas, India's first locally-built Light Combat Aircraft (LCA), before its induction into the Indian Air Force at the Hindustan Aeronautics Limited (HAL) Airport in Bengaluru, India, July 1, 2016. (Photo by Abhishek N. Chinnappa/Reuters)

Thomas jumps into the water from a spring board at a public swimming pool in Mengen, Germany, 28 August 2016. (Photo by Thomas Warnack/EPA)

Indian children work nearby to their parents at a construction project in front of the Jawaharlal Nehru Stadium on January 30, 2010 in New Delhi, India. The children accompany their parents to the work site, where if they are prepared to work, they will receive money for bread an milk and be provided with dinner by the contractor. The sheer scale of the project has drawn an enormous population of migrant workers from all over India.

This picture taken on April 12, 2017 shows men carrying bamboo through a forest near Dashan village near the city of Lin'an, Zhejiang Province. Lin'an is in a area of eastern Zhejiang province whose rich bamboo forests are estimated to supply up to two-thirds of China's bamboo shoots, plus a range of other products derived from the fast-growing plant that are produced both for domestic and overseas markets. (Photo by Johannes Eisele/AFP Photo)