The genetic changes cause the bodies of the insects to attack the Plasmodium parasite, blocking its development.

VOA: special.2010.04.20

Although Democrats control both houses of the legislature, their Senate majority is not large enough to prevent Republicans from blocking legislation through parliamentary maneuvers.

VOA: standard.2009.03.22

Pakistani security forces largely succeeded in preventing mass demonstrations by political activists and lawyers earlier this week by blocking roads and arresting hundreds of protest leaders.

VOA: standard.2009.03.15

You are stopping the productivity of the country. You are really blocking the production and this is not the kind of development we are looking for,"

VOA: standard.2009.08.28