11.   Only a decade ago, U.S. policymakers devoted vast efforts to block the advances of Guardado and his presumably communist comrades across Central America.

12.   Organizers said they would try to enter the Turkish-occupied north as they did last year, when bloody clashes broke out as Turkish troops blocked their advance.

13.   A similar attempt by motorcyclists last year resulted in bloody clashes between the protesters and Turkish troops that blocked their advance.

14.   Hundreds of Uzbek soldiers also were reported heading south to block the advance of the Taliban troops who had moved through the Salang pass in the Hindu Kush mountains.

15.   Hundreds of Uzbek soldiers were reported to be heading south to block the advance of the Taliban army.

16.   Lapuente commented on the need to block the advances of defenders Cafu and Roberto Carlos, who often start the attack from the flanks.

17.   The medicines work by blocking the advance of flu through the body.

18.   The rebel troops returned to their barracks by Tuesday night, their advance blocked by pro-government soldiers.

19.   The rebels troops returned to their barracks by Tuesday night after their advance was blocked by pro-government soldiers.

20.   The students marched out of the university but police blocked their advance onto a nearby main road.