He says North Korea's actions block any exchange of people and resources between the Koreas.

VOA: standard.2010.05.27

Dr.Correll says he hopes research will help design new drugs to block the weight gain.

VOA: standard.2010.07.08

In light of threats from the Israelis to block the flotilla of ships, Zehra Ozturk says she and her fellow pro-Palestinian activists from Turkey are not thinking about a blockade.

VOA: standard.2010.05.28

He says these forces could block the political process.

VOA: standard.2009.10.26