And he is praising four committees in Congress for agreeing on what he calls "a difficult and complex challenge."

VOA: standard.2009.08.08

I am not going to walk away from the American people. I am not going to walk away on this challenge.

VOA: standard.2010.02.06

He says fighting traffic congestion, he adds,is an on-going challenge because this urban area continues to attract more jobs and more people.

VOA: standard.2010.07.26

Another problem is access. Connecting informal communities to the city's water pipeline is a challenge because many are living on the land illegally.

VOA: standard.2010.08.04

"So I can challenge somebody and they can challenge me just on an on-going basis.

VOA: standard.2010.07.16

Republicans have taken aim at that, as they continue to attack Mr.Obama on several fronts and challenge the White House over deficit spending and rising debt.

VOA: standard.2010.07.19

As President Obama loses ground in the debate on overhauling health care, he is using his weekly Internet address to challenge what he calls "phony claims" by his critics.

VOA: standard.2009.08.22

And last June,says Sittenfeld, the House passed the American Clean Energy and Security Act, the first bill out of either chamber of Congress to directly take on the challenge of global warming.

VOA: standard.2010.02.25

On the second day of her Moscow visit, at the end of a European tour, U.S.Secretary of State Hillary Clinton voiced concern at recent attacks on activists and reporters willing to challenge the Kremlin.

VOA: standard.2009.10.14

For Garson,it has been a challenge to put aside his concerns about Haiti, and focus on football and the most important game of his career, but he has a simple message to Haitians.

VOA: standard.2010.02.04