Kirby Chambliss of the United States flies in formation with Matt Hall of Australia, Yoshihide Muroya of Japan and Nigel Lamb of Britain prior to the third stage of the Red Bull Air Race World Championship in front of the Petronas Towers in Kuala Lumpur, Malaysia, on May 15, 2014. (Photo by Joerg Mitter/Red Bull via Reuters)

Large trumpet vines spread across electrical lines next to a highway in Kinston, N.C., on June 23, 2014. (Photo by Janet S. Carter/Kinston Free Press via AP Photo)

Miniature spring-wound 35-mm film camera in a modified cigarette pack. The Tessina’s small size and quiet operation provided more options for concealment than most commercially available models. (Photo by Central Intelligence Agency)

Hot air balloons fly over the sky in Chiang Mai province, northern Thailand, December 6, 2014. The two-day International Balloon festival 2014 featuring balloon pilots from Germany, Spain, Netherlands, Britain, and Czech Republic is held on December 06-07 2014 to celebrate Thai King Bhumibol Adulyadej's 87th birthday and also aimed to promote the tourism industry in Chiang Mai northern city. (Photo by Pongmanat Tasiri/EPA)

A Filipino worker arranges roasted pigs which they sell in suburban Quezon city, Philippines on Tuesday, December 23, 2014. Roasted pig is popular during Filipino celebrations and traditionally served during a Christmas eve dinner called “Noche Buena” in this predominantly Roman Catholic nation. (Photo by Aaron Favila/AP Photo)

An Afghan woman fills containers with water near her temporary shelter at an internally displaced person's (IDP) camp on the outskirts of Herat, Afghanistan, January 21, 2015. Dozens of families are living in temporary shelters even in harsh winters and most depend on aid distributions by the United Nations High Commissioner for Refugees (UNHCR). (Photo by Jalil Rezayee/EPA)

A Houthi follower with fake blood on his clothes lies on the ground to represent a victim as others perform a war dance during a ceremony marking the first anniversary of the Houthi movement's takeover of Yemen's capital Sanaa September 21, 2015. (Photo by Khaled Abdullah/Reuters)

Kurdish guard women from the civilian protection unit which supports the Democratic Forces of Syria, cheer near the Syrian town of al Houl in Hasaka province, after the Democratic Forces of Syria took control of the area, November 14, 2015. A U.S.-backed Syrian rebel alliance on Friday captured the town of al Houl in Hasaka province, which had been held by Islamic State militants, a spokesman for the Kurdish fighters, part of the grouping, said. It was the first significant advance against IS by the Democratic Forces of Syria, which was formed last month. (Photo by Rodi Said/Reuters)