In this September 10, 1977, file photo, from left, Hua Guofeng, Chinese Communist Party (CCP) chairman and Mao Zedong's immediate successor; Ye Jianying, CCP vice chairman and future ceremonial head of state; Deng Xiaoping, no formal titles at the time but soon to emerge as paramount leader during the reform era; Li Xiannian, CCP vice chairman and future president; Wang Dongxing, head of the leadership bodyguard unit who helped topple the Gang of Four, view the body of later Chinese leader Mao Zedong in Beijing. (Photo via AP Photo)

Adventurer Sam Cossman movies towards the huge lava lake wearing a custom built industrial proximity heat suit on December 20, 2014 in Ambrym, Vanuatu. (Photo by Conor Toumarkine/Barcroft Media)

An African giant pouched rat sniffs for traces of landmine explosives at APOPO's training facility in Morogoro on June 17, 2016. APOPO trains the rats to detect both tuberculosis and landmines at its facility. Every year landmines kill or maim thousands of people worldwide. The trained rats sniff for explosive and so are able to detect the presence of landmines far faster than conventional methods which involve metal detection. (Photo by Carl De Souza/AFP Photo)

A picture made available on 20 June 2016 shows people praying as they wait to break the fast during the Muslim holy month of Ramadan, in Karachi, Pakistan, 19 June 2016. Muslims around the world celebrate the holy month of Ramadan by praying during the night time and abstaining from eating and drinking during the period between sunrise and sunset. Ramadan is the ninth month in the Islamic calendar and it is believed that the Koran's first verse was revealed during its last 10 nights. (Photo by Shahzaib Akber/EPA)

A woman controls a ball on Ipanema beach in Rio de Janeiro, Brazil, April 14, 2016. As hundreds of thousands of tourists begin descending on Rio de Janeiro for the Olympics that start August 5, the headlines have focused on the street violence, the Zika virus, the water pollution and the rush to finish venues and transport. But Rio, known by Brazilians as the “Marvelous City”, glistens despite it all. The beach is a way of life here. (Photo by Nacho Doce/Reuters)

Cambodian children sleep on a pavement at a park in Phnom Penh on July 8, 2016. (Photo by Tang Chhin Sothy/AFP Photo)

Men carry a dog, wearing a costume and seated on a stool, as a form of respect as they believe that dogs found water for their ancestors, during a local festival for the Miao ethnic minority in Jianhe county, Guizhou Province, China, August 14, 2016. (Photo by Reuters/China Daily)

Baby giraffe of Niger (Giraffa Camelopardalis) “Kenai” (R), born on August 25, 2016, kisses his mother “Dioni” on August 31, 2016 at the zoo of La Fleche, northwestern France. (Photo by Jean-Francois Monier/AFP Photo)