And because the key component of solar cells is an expensive, highly purified form of silicon, there's a real economic benefit to this design.

VOA: standard.2010.02.19

For that reason, and because the Taliban is continuing its resurgence, General Myers says President Obama should take enough time to get the strategy right, but not too much time.

VOA: standard.2009.10.16

He tested the cement, and says less could be used because the rice hull ash makes it a stronger building material.

VOA: special.2009.12.01

The Italian cities of Genoa and Venice became powerful because they were at the center of the spice trade.

VOA: special.2010.06.01

Toyota is recalling millions of cars and trucks around the world because of cases where vehicles have sped up unexpectedly.

VOA: special.2010.02.05

And,he likes to work near the other glass artists in the school because they can exchange ideas and methods.

VOA: special.2009.09.16

She says it remains fresh and unusual because the event does not try to tell society's views about the performing arts.

VOA: special.2009.08.05

He says the substances are especially dangerous because they travel through the air and stay in the atmosphere, soil and water.

VOA: special.2009.06.23

For example, Gladys Knight and the Pips left Motown in nineteen seventy-three because they never felt completely accepted by the company.

VOA: special.2009.05.11

It was not possible to travel straight through because of the Rocky Mountains and the deep snow that fell in winter.

VOA: special.2010.04.26

DDT and other pesticides had become popular with the public and the government because they were so effective.

VOA: special.2010.03.14

Scientists are able to measure the strength and position of earthquakes because there are hundreds of seismic monitoring stations around the world.

VOA: special.2011.06.07

Makers of the devices say they kill bacteria and viruses because they help to remove the wetness that germs need to survive.

VOA: special.2009.07.14

And,the job requires careful attention to detail, because even the smallest observation can lead to solving a crime.

VOA: special.2010.05.05