21.   The Serbian troops refused requests to move the tree they had used to block the road.

22.   The Supreme Court says that copyright laws cannot be used to block unauthorized imports of name-brand perfume, cosmetics, jewelry, home electronics and other goods.

23.   The veto could be used to block new entitlement programs, however.

24.   Underlying the court decision were the vague criteria the Communications Decency Act could use to block material from the Internet.

25.   Constant rain Wednesday night and drizzle early Thursday also would have made it difficult for protesters to light the flaming tire barricades they use to block traffic.

26.   Dissidents demanded that the legislature accelerate political reforms, spend more on education and abolish household registration rules used to block farmers from migrating to cities.

27.   In response to the problem, the White House enhanced filters used to block access to inappropriate sites.

28.   It was the second time the decree has been used to block a candidate from entering the election.

29.   They also may have been sabotaged by rain through Wednesday night that would have made it difficult to light the flaming tire barricades used to block traffic.

30.   While acknowledging the potential benefit of the rice, they say that should not be used to block efforts to require stricter regulation.