21.   It works by blocking formation of the liver-destroying toxins, Haffner said.

22.   Political scientist Fernando Rospigliosi, who has studied civil-military relations, was skeptical Montesinos could lead the military to block the formation of a new democratic government.

23.   Several days ago, he had warned that Cambodia could face a new political crisis if the opposition parties tried to block the formation of a new government.

24.   Several days ago, Hun Sen had warned that Cambodia could face a new political crisis if the opposition parties tried to block the formation of a new government.

25.   Some commentators have suggested Walesa is trying to block formation of a government as an excuse to call early elections and drive the leftists out of parliament.

26.   The babies have a defective gene that literally blocks lymphocyte formation.

27.   Talks resumed Wednesday to try to iron out differences that have blocked formation of a coalition of conservatives and an Islamic party.

28.   The discovery puts researchers on track to isolate a compound from angiostatin that could work more directly to block blood vessel formation, he said.

29.   The opposition, protesting alleged election fraud, threatened to boycott parliament, which would block the formation of a new government.

30.   The reshaped molecule works by blocking formation of blood vessels that would supply oxygen and nutrients to cancer cells.