He was forty years old. Over the years,historians and medical experts have tried to explain the cause of Poe's death.

VOA: special.2009.02.02

Scientists in the United States and other countries have been working to explain the mysterious disappearances of bees.

VOA: special.2009.09.22

This is not a subject that many media programs have tried to explain to very small children.

VOA: special.2009.11.27

He discusses how scientists over the years have identified the experience and developed theories to explain it.

VOA: special.2010.02.24

So they have tried to explain their findings on a Harvard Web site.

VOA: special.2010.02.03

"I am more than satisfied." "I cannot explain. It is more than I expected, because to meet the pope personally you have to be something special."

VOA: standard.2010.04.18

They have been invited to Australia to explain their creations to thousands of visitors.

VOA: standard.2009.12.09

"Using x-ray crystallography to obtain snapshots of the ribosome in action, they have been able to explain how the ribosome selects and couples together amino acids to form proteins."

VOA: standard.2009.10.07