Three scientists based in the United States have won the two thousand nine Nobel Prize for Physiology or Medicine.

VOA: special.2009.10.07

He says there are more than three hundred thousand small objects or pieces of debris in orbit that are larger than one centimeter.

VOA: special.2009.04.01

Last year,more than six hundred twenty thousand, or three and a half percent, were international students.

VOA: special.2009.02.05

Twenty-three thousand Union soldiers were killed,wounded or missing.

VOA: special.2009.11.05