Singers in the St. Paul's Cathedral choir in London rehearse ahead of Christmas services on Monday, December 22. Kirsty Wigglesworth/AP

Officers salute during the New York Police Department promotion ceremony on Friday, December 19. CARLO ALLEGRI/Reuters/Landov

In this photo provided by the Korea Hydro & Nuclear Power Co., workers participate in an anti-cyberattack exercise at Wolsong power plant on Monday, December 22, in Gyeongju, South Korea. Korea Hydro Nuclear Power/Getty Images

After a Jordanian military plane crashed over Raqqa province in Syria, ISIS took the pilot hostage on Wednesday, December 24, Jordanian state-run news agency Petra said. The U.S. military said the militants did not down the aircraft. ISIS

The Dow closed above the 18,000 milestone for the first time ever Tuesday, December 23. The market jump came as investors learned that the U.S. economy grew at an impressive 5% pace in the third quarter. It was the strongest quarter of growth since 2003. Seth Wenig/AP

A Pakistani boy decorates a tree before Christmas in Islamabad's slums, on Tuesday, December 23. B.K. Bangash/AP

U.S. Marines hold up an American flag before Navy played San Diego State in the Poinsettia Bowl NCAA bowl game on Tuesday, December 23, in San Diego. Navy won 17-16. Gregory Bull/AP

Pope Francis delivers the "Urbi et Orbi" message and blessing to the world from St. Peter's Basilica during the Vatican Christmas celebrations on Thursday, December 25. Alessandra Benedetti/Corbis

Hot-air balloons fly over Cappadocia, a historical region in Turkey's Central Anatolia, on Tuesday, December 23. Murat Oner Tas/Anadolu Agency/Getty Images

Beachgoers dressed as Santas spend Christmas Day relaxing in the sunshine of Santa Monica Beach, in California, on Thursday, December 25. Mikael Buck/Rex/REX USA

Children walk through a flooded street in Jakarta, Indonesia, on Tuesday, December 23. BEAWIHARTA/Reuters/Landov

Fog spreads over the Potomac River in Alexandria,Virginia, at the Woodrow Wilson Bridge on Wednesday, December 24. PAUL J. RICHARDS/AFP/Getty Images

An Indian Sikh takes a dip near the Golden Temple in Amritsar on Wednesday, December 24, on a foggy morning. NARINDER NANU/AFP/Getty Images

Police move hundreds of "Black Lives Matter" protesters out of the Mall of America after they disrupted holiday shoppers on Saturday, December 20, in Bloomington, Minnesota. Adam Bettcher/Getty Images

A man looks out a broken window after clashes between Bangladesh Nationalist Party supporters and government supporters on Wednesday, December 24, before BNP chairperson Khaleda Zia arrived at court. Suvra Kanti Das/ZUMA Wire

A man crosses the street near Forward Operating Base Fenty at sunrise in Afghanistan on Friday, December 19. LUCAS JACKSON/Reuters/Landov

Migratory birds fly on Poyang Lake on Sunday, December 21, in east China. ChinaFotoPress/Getty Images

An Israeli soldier walks with a detained Palestinian teenager who the military said illegally crossed into Israel near the Gaza border, Wednesday, December 24. Tsafrir Abayov/AP

Two fishing boats registered in Papua New Guinea are destroyed by the Indonesian navy after they were seized for alleged illegal fishing on Sunday, December 21. ANTARA FOTO/Reuters/Landov

Workers put the final touches on a sculpture at the 27th Harbin Sun Island International Snow Sculpture Art Expo on Saturday, December 20, in Harbin, China. ChinaFotoPress/Getty Images

Chasity Magee reacts near her family's mobile home in Columbia, Mississippi, on Wednesday, December 24. The home was flipped on top of a neighbor's during a storm that killed four in the state. Rogelio V. Solis/AP