Pakistani supporters of cricketer-turned politician Imran Khan and Canadian cleric Tahir ul Qadri beat a riot policeman during an anti-government protest in Islamabad on September 1, 2014. Hundreds of protesters trying to topple Pakistan's government briefly seized the state broadcaster on September 1, intensifying the political crisis gripping the nuclear-armed nation. Deadly clashes since the weekend have raised the spectre of military intervention which gained ground after one disillusioned opposition leader said the protesters were acting according to a plan devised by the army. (Photo by Aamir Qureshi/AFP Photo)

View of the “Sunset Lake” hot spring with it's unique colors caused by brown, orange and yellow algae-like bacteria called Thermophiles, that thrive in the cooling water turning the vivid aqua-blues to a murkier greenish brown, in the Yellowstone National Park, Wyoming on June 1, 2011. Yellowstone National Park, was established by the U.S. Congress and signed into law by President Grant on March 1, 1872. The park is located primarily in the U.S. state of Wyoming, though it also extends into Montana and Idaho and was the first national park in the world. It is known for its wildlife and its many geothermal features, especially the Old Faithful Geyser. (Photo by Mark Ralston/AFP Photo)

A competitor laughs while taking part in the office chair race ISU-1 Grand Prix in Tainan, southern Taiwan April 24, 2016. It was the first time such a race was held in Tainan, as part of the “ISU-1 GP” (Grand Prix) that began in Japan in 2010, according to businesses on Jhengsing Street and Haian Road in the city's West Central District and the city's Tourism Bureau, which organized the event. The fastest rider only took six seconds to complete the 30-meter race. (Photo by Tyrone Siu/Reuters)

Yak near Yamdrok lake, Tibet. It is a long-haired bovinae found throughout the Himalayan region of south Central Asia, the Tibetan Plateau and as far north as Mongolia and Russia. The Tibetan economy is dominated by subsistence agriculture. Due to limited arable land, the primary occupation of the Tibetan Plateau is raising livestock, such as sheep, cattle, goats, camels, yaks, dzo, and horses. The Tibetan yak is an integral part of Tibetan life. (Photo by Dennis Jarvis)

Seiichiro Nishimoto, CEO of Shelter Co., poses wearing a gas mask at a model room for the company's nuclear shelters in the basement of his house in Osaka, Japan on April 26, 2017. With nearby North Korea increasing its show of power day by day with missile launches and nuclear tests, people in Japan are preparing for the worst by building private nuclear shelters, Reuters reports. (Photo by Kim Kyung-Hoon/Reuters)

The North Side Skull & Bone Gang stand together during the wake up call for Mardi Gras, Tuesday, February 9, 2016, in New Orleans. Their costumes are intended to represent the dead and they bring a serious message, reminding people of their mortality and the need to live a productive and good life. (Photo by Brynn Anderson/AP Photo)

Lindsay Mann (L) and Anabella Mowbray kiss as they take photos of themselves laying in the confetti on 7th Avenue in Times Square on New Year's Eve in New York January 1, 2015. (Photo by Carlo Allegri/Reuters)

A Pakistani scavenger girl writes on a notebook she collected from a garbage, while another girl sits next to her in Lahore, Pakistan, Wednesday, April 1, 2015. Thousands of children pick recyclable items from waste dumping points to earn living for their poor families. (Photo by K. M. Chaudary/AP Photo)