It is a long-term endeavor and we both are united to fight against this endeavor, which is challenging our way of life and wants to challenge the way of life with the world."

VOA: standard.2009.05.13

He says he likes that the music is more challenging than what he plays with his school orchestra.

VOA: special.2010.06.21

"It is extraordinarily challenging and that is why Calderon is fighting a war on multiple fronts,"

VOA: standard.2009.12.18

Making the transition from high school to college is often a challenging experience.

VOA: standard.2009.12.04

But the acquisition of radioactive material for a so-called 'dirty bomb,' which is radioactive material that is dispersed with a conventional explosive device, that is not that challenging.

VOA: standard.2009.05.01

"That character piece is the foundation. As we like to say, when you are put in very challenging environments, like the southern Helmand province of Afghanistan, or recently in western Iraq.

VOA: standard.2010.04.06

"The market is definitely very, very challenging. Our airline customers are feeling the pain of the situation and of the environment but clearly we're starting to see some signs of stabilization in the market in terms of the economy,".

VOA: standard.2009.06.16

"The prime minister is leading Greece through challenging times, but as I told him during our meeting in the Oval Office today, whether in good times or in bad times, the people of Greece will always have a friend and a partner in the United States."

VOA: standard.2010.03.11