Attorney General Eric Holder has called the case one of the most serious threats since the attacks of September eleventh, two thousand one.

VOA: special.2009.10.17

When he took office several months later, he faced the most serious crisis in American history.

VOA: special.2009.07.16

The most serious problem was what to do with property owned by the federal government.

VOA: special.2009.07.23

He would enter office facing the most serious crisis in American history.

VOA: special.2009.07.09

Heat stroke is the most serious disorder linked to hot weather.

VOA: special.2010.07.27

Getting enough good air to breathe became the most serious problem.

VOA: special.2009.07.22

The most serious incident took place in Chicago's Haymarket Square.

VOA: special.2010.05.06

The most serious problem involved Spain.

VOA: special.2010.07.15

He has described the attacks, as the "biggest,most complicated and most serious series of murders in the history of Hungarian criminology."

VOA: standard.2009.08.22

Clark sees traffic congestion as one of the most serious problems of our time - for a variety of reasons.

VOA: standard.2010.07.26

The most serious occurred in 1918 when upwards of 50 million people are believed to have died.

VOA: standard.2009.05.14

It was the most serious clash on the border since the Lebanon War four years ago, when Israel battled the Islamic guerrilla group Hezbollah.

VOA: standard.2010.08.03

The most serious abuses include extra-judicial executions and wide scale rapes and sexually based gender violence.

VOA: standard.2009.09.12

The United Nations peacekeeping force in south Lebanon has backed Israel's version of events following the most serious border clash in four years on Tuesday.

VOA: standard.2010.08.04

First polls showed that most voters believe Grybauskaite has what it takes to lead the country out of its most serious economic crisis in years.

VOA: standard.2009.05.17

It was the most serious border clash since the Lebanon War four years ago.

VOA: standard.2010.08.05

"It gives the nutrients and the immune factors that are important for protecting infants against the most serious infections they can get, which is diarrhea and pneumonia,"

VOA: standard.2009.08.01

Many of the most serious complaints allege supporters of President Karzai rigged the results at polling stations on Election Day in three provinces strongholds of the incumbent.

VOA: standard.2009.09.08

The failed terror bomb plot constitutes Mr.Obama's most serious national security test to date, and the president has been quick to acknowledge that there is plenty of room for improvement.

VOA: standard.2010.01.06

But these are things that can be minimized and lessened if Mexico and the United States work together, identify the most serious problems and try to fight them in very focused ways."

VOA: standard.2009.12.18

"And that's the duty of everyone who believes in justice and in deterring the gravest and most serious types of crimes that the United Nations was partially set up to prevent after the Second World War, and continues to fail to prevent."

VOA: standard.2009.09.07

A political scientist at the University of Zimbabwe, Eldred Masunungure, says the police are the most serious offenders of the political agreement and the hard core of top officers are determined to hang on to power for as long as possible.

VOA: standard.2009.09.15

Most scientists agree that climate change is a serious problem that requires the attention of people and governments around the world.

VOA: special.2009.06.03

Although hot weather just makes most people feel hot, it can cause serious medical problems, even death.

VOA: special.2010.07.27