US

Hoover Dam, a concrete arch-gravity dam in the Black Canyon of the Colorado River on the border between the US states of Arizona and Nevada. Hoover Dam ,finished in 1936, impounds Lake Mead, the largest reservoir in the United States by volume. The dam's generators provide power for public and private utilities in Nevada, Arizona, and California. Hoover Dam is a major tourist attraction; nearly a million people tour the dam each year.

Joe Klamar/AFP

The sun rises over the Hoover Dam, a concrete arch-gravity dam in the Black Canyon of the Colorado River on the border between the US states of Arizona and Nevada. The Hoover Dam was finished in 1936 and impounds Lake Mead, the largest reservoir in theUS by volume.

Filipino activists hold paper mache skulls  painted with US flags as they march outside the US embassy in Manila, Philippines on Monday in a rally condemning the upcoming visit of US President Barack Obama to the country. Activists also called for an end to the presence of US troops in the country and the Visiting Forces Agreement (VFA).

Dennis M. Sabangan/EPA

Filipino activists wear painted skull masks at a march outside the US embassy in Manila, Philippines, on Monday to condemn an upcoming visit by US President Barack Obama. Activists also called for an end to the presence of US troops in the country and the visiting forces agreement.

Largest Freefall Formation world record attempt in Arizona USA...epaselect epa04150210 222 skydivers from World Team attempt to break the world record for the Federation Aeronautique Internationale (FAI) Largest Sequential Freefall Formation attempt at Skydive Arizona in Eloy, Arizona, USA, 01 April, 2014.

Roy Dabner/EPA

222 skydivers from World Team attempt to break the world record for the Federation Aeronautique Internationale (FAI) Largest Sequential Freefall Formation attempt at Skydive Arizona in Eloy, Arizona, US on Monday. Read more

Lee Montgomery sits and waits to sign up for health care insurance at the business office of Parkland Hospital in Dallas, Monday. According to Montgomery, he as tried several times to sign up for private heath insurance in the online markets created by President Obama's heath care law, but has been unable to so he came to Parkland for face to face help.

LM Otero/AP

Lee Montgomery waits to sign up for healthcare insurance at the office of Parkland Hospital in Dallas, on Monday. Mr Montgomery says he has tried and failed several times to sign up for private heath insurance in the online markets created by President Barack Obama’s healthcare law, so has opted to sign up in person instead.

Amphibious assault vehicles of the South Korean Marine Corps throw smoke bombs as they move to land on shore during a U.S.-South Korea joint landing operation drill in Pohang...Amphibious assault vehicles of the South Korean Marine Corps throw smoke bombs as they move to land on shore during a U.S.-South Korea joint landing operation drill in Pohang March 31, 2014. The drill is part of the two countries' annual military training called Foal Eagle, which began on February 24 and runs until April 18.  North Korea declared a no-sail warning on Monday for areas off its west coast near a disputed border with South Korea and has notified the South that it will conduct firing drills, a South Korean government official said. The warning comes amid heightened tensions surrounding the North after the U.N. Security Council condemned Pyongyang for its mid-range missile launches last week, just as the leaders of South Korea, Japan and the United States met to discuss the North's arms programme.

Kim Hong-Ji/Reuters

Amphibious assault vehicles of the South Korean Marine Corps throw smoke bombs as they land onshore during a US-South Korea joint landing operation drill in Pohang. The drill is part of the two countries’ annual military training called Foal Eagle, which began on February 24 and runs until April 18.

U.S. President Barack Obama waves as he leaves Rome's airport...U.S. President Barack Obama waves as he leaves Rome's airport March 28, 2014. REUTERS/Giampiero Sposito  (ITALY - Tags: POLITICS)

Giampiero Sposito/Reuters

U.S. President Barack Obama waves as he leaves Rome‘s airport. Read more

Wind-driven waves crash on a sea wall in Scituate, Mass., Wednesday, March 26, 2014. Cape Cod and the islands were expected to bear the brunt of the spring storm that struck full force Wednesday. The storm could drop up to 10 inches of snow.

Michael Dwyer/AP

Wind-driven waves crash on a sea wall in Scituate, Massachusetts. Cape Cod and the islands were expected to bear the brunt of the spring storm that struck full force Wednesday. The storm could drop up to 10 inches of snow.

US First Lady Michelle Obama (C) perform...US First Lady Michelle Obama (C) performs "tai chi" with students from the Chengdu No7 High School in Chengdu in China's southwest Sichuan province on March 25, 2014. Michelle Obama arrived in China on March 20 with her mother and daughters to kick off a seven-day, three-city tour where she will focus on education and cultural exchange.   AFP PHOTO / Peter PARKSPETER PARKS/AFP/Getty Images

Peter Parks/AFP

US First Lady Michelle Obama performs t’ai chi with students from the Chengdu No 7 High School in Chengdu, in China’s southwest Sichuan province. Michelle Obama arrived in China last week with her mother and daughters to start a seven-day, three-city tour where she will focus on education and cultural exchange. Read more

US First Lady Michelle Obama (C) and Peng Liyuan, wife of Chinese President Xi Jinping are escorted by officials as they visit the Forbidden City in Beijing on March 21, 2014.  Michelle Obama arrived in Beijing with her mother and daughters to kick off a seven-day, three-city tour where she will focus on education and cultural exchange.

Andy Wong/AFP

US first lady Michelle Obama and Peng Liyuan, wife of Chinese president Xi Jinping, are escorted by officials as they visit the Forbidden City in Beijing on Friday. Mrs Obama arrived in Beijing with her mother and daughters to kick off a seven-day, three-city tour where she will focus on education and cultural exchange.

A Filipino student shouts anti-US slogans outside the US embassy in Manila, Philippines, 21 March 2014 in a rally condemning the docking of the USS Blue Ridge and the upcoming visit of US President Barack Obama to the country. Activists also called for an end to the presence of US troops in the country and the Visiting Forces Agreement (VFA). Obama is to visit Japan, South Korea, Malaysia and the Philippines in late April. The trip is part of his efforts to broaden US engagement in the Asia-Pacific region on all fronts, from strategic security issues to trade and diplomacy. Obama had originally planned an Asia trip for late 2013, but was forced to cancel during the budget and debt limit crisis that closed the US government for more than two weeks in October.

Dennis M. Sabangan/EPA

A Filipino student protests outside the US embassy in Manila, Philippines, in a rally condemning the docking of the USS Blue Ridge and the upcoming visit of US President Barack Obama. Activists also called for an end to the presence of US troops in the country and the Visiting Forces Agreement.