In this photo released by Xhinhua News Agency, a rescuer evacuates residents near the site of a chemical plant blast in Zhangzhou, southeast China's Fujian Province Tuesday, April 7, 2015. Six people have been hospitalized and hundreds of firefighters deployed to battle a blaze sparked by an explosion at Goure PX Plant that produces the toxic chemical paraxylene, officials said Tuesday. (Photo by Wei Peiquan/AP Photo/Xinhua)

A worker manually changes the direction of the bonde, the typical tram line in Santa Teresa neighborhood, using a rope in Rio de Janeiro, Brazil, September 9, 2015. The Santa Teresa bonde, called “Bondinho” in Portuguese, is running with passengers as a part of a test period, after the service was suspended in 2011 following an accident that killed six people, according to residents. (Photo by Pilar Olivares/Reuters)

A Pakistani monkey handler Naseer Khan plays flute to attract passers by for a monkey show to earn his living in Islamabad, Pakistan, Monday, September 7, 2015. (Photo by B. K. Bangash/AP Photo)

Models smoke during a break at Sevilla de Boda (Seville Wedding) fashion show in the Andalusian capital of Seville November 27, 2015. (Photo by Marcelo del Pozo/Reuters)

A little girl holding her newborn sister waits for their turn in a queue during a vaccination campaign under the supervision of the Syrian Arab Red Crescent (SARC) humanitarian nonprofit organization, in the besieged Syrian town of Douma, Syria, 23 May 2017. According to a statement from SARC, in the city of Douma some 12,809 children under the age of five were immunized in a vaccination campaign to prevent measles and poliomyelitis. The campaign was the first of its kind with the participation of 100 volunteers. SARC has been delivering vaccines to 17 health centers approved for vaccination campaigns in towns and villages in the Eastern Ghouta area. (Photo by Mohammed Badra/EPA)

Armed Yemeni children sit in the back of a pick up truck with fighters loyal to Yemen's Saudi-backed President Abedrabbo Mansour Hadi in the Dar saad neighbourhood of the southern Yemeni city of Aden on May 10, 2015, as they continue to battle Shiite Huthi rebels. (Photo by Saleh Al-Obeidi/AFP Photo)

“Show us our butts! Mucawana tribe – Angola. In Soba village, the Muhacaona (Mucawana) tribe, perhaps the best place i have visited. They use cow dung and fat to make this so nice haircut, and love the beads. They asked me to make pictures of their backs... and butts to see on the camera screen if everything was perfect!”. (Photo and comments by Eric Lafforgue)