The theory explains that as the sea floor spreads, the tectonic plates are pushed and pulled in different directions.

VOA: special.2011.01.04

The Doppler effect explains changes in the length of light waves or sound waves as they move toward you or away from you.

VOA: special.2009.04.29

Players could sign with any team once their contract expired, as sports economist Andrew Zimbalist explains.

VOA: special.2010.07.26

People use a metal call box with a push-to-talk button to connect to a live operator, as Rose Shuman explains: "You just push a button, a big green button, and that will connect you directly to our operators who are sitting in front of computers, and speak your language.

VOA: special.2009.10.12

Gomez explains that many Latino immigrant families see mental illness as a moral failure, a problem to be hidden.

VOA: standard.2010.07.22

He explains his two prison sentences for assault and robbery as errors of youth more than 40 years ago.

VOA: standard.2010.02.01

Bolt jokes around and teases his competitors before races, as 200-meter bronze medalist Wallace Spearmon of the United States explains.

VOA: standard.2009.08.21

He explains that businesses such as Nuru Design are examples of what a "green economy" would be like.

VOA: standard.2010.02.24

However as Ronald Suny with the University of Chicago explains, the Turkish government has a diametrically opposed view.

VOA: standard.2010.03.19

She explains that the strategy did not work as predicted because of what's called a population level effect.

VOA: standard.2010.03.22

Garza explains that on previous census forms, Latinos could only claim their race as 'white' or 'non-white'.

VOA: standard.2010.04.05

As political analyst Jacek Kucharczyk explains, this new approach represents a dramatic shift.

VOA: standard.2010.06.17

She explains that she voted for herself as in her words "Lithuania's local political establishment is so boring for people, that they want to see some new faces."

VOA: standard.2009.05.17

More than 200 individuals and organizations were nominated this year, but as Jagland explains, Barack Obama won for giving the world hope for a better future and for striving for a nuclear-free world.

VOA: standard.2009.10.09

(recording) As one woman in Warsaw explains, politicians and the press have been getting very upset about the missile shield, but ever since Poland joined NATO ordinary Poles have felt much stronger and more secure.

VOA: standard.2009.10.22

And as the story acknowledges, that's where we'll be," He explains, as Pentagon officials have in the past, that the deployment of major combat or training units always requires the deployment of additional support troops.

VOA: standard.2009.10.13

Twenty-two percent of blacks, The fact that almost twice as many blacks don't have health care as whites in part explains why black children are twice as likely to die before their first birthday as white kids.

VOA: standard.2009.09.09