Scientists say it formed when high sea levels flooded the middle of North America, splitting the continent in two for millions of years during the late Cretaceous period.

VOA: special.2010.10.05

Last year,President Obama's approval rating was high as Arabs were hopeful about his Middle East policies.

VOA: standard.2010.08.06

Hanle says the focus is on offering special programs for teachers at middle schools and high schools because that's when the students start to lose interest in studying science.

VOA: standard.2009.11.25

In the heart of the Navajo Nation, in the middle of the high desert many kilometers from any town, one finds the only point in America where four states come together.

VOA: standard.2010.03.22