But he also admitted he will not be able to prevent all fraud in the second round.

VOA: standard.2009.10.23

They acknowledge they will not be able to prevent similar practices in the future, but they are hopeful their study will promote changes for the better.

VOA: standard.2009.03.21

The defense minister, General Abdul Rahim Wardak, noted that even nations with "100-fold" more security resources, mentioning the United States, Britain,Spain,India, Indonesia and Pakistan, have not been able to prevent all attempted terrorist attacks.

VOA: standard.2009.08.16

Several studies have not been able to show that taking vitamin supplements in addition to a balanced diet helps to prevent disease.

VOA: special.2010.09.14

But researchers hope that one day they will be able to do that though a simple blood test, and prevent more deaths like Suzanna's.

VOA: standard.2010.02.08

"If you've ever worked on these cartel cases as I have as a prosecutor, you know a wall is not the best way to spend our dollars to prevent these drugs from coming into the United States and being able to apprehend and prosecute the smugglers themselves,".

VOA: standard.2009.03.24