21.   Officials said they could not wait for the test results Tuesday before acting to prevent an outbreak from spreading.

22.   Similarly, the British government has said it will act to prevent any use of jamming devices.

23.   The dollar fell for a fourth day amid concern Japan may act to prevent the U.S. currency from rallying, traders said.

24.   The dollar fell against the yen for a fourth day today amid concern Japan may act to prevent the U.S. currency from rallying, traders said.

25.   The government acted to prevent clashes between the Catholic minority and the Protestant majority in this predominantly Protestant British province.

26.   The treatment stimulates the body to produce antibodies that may act to prevent an allergic reaction.

27.   They are factors even for a president and a public who claim we must always act to prevent genocide.

28.   They feared that convicting her of murder would send a message to other Mexican women that they could not act to prevent a rape.

29.   Turkey said it was acting to prevent the slaughter of ethnic Turks by the ethnic Greek majority.

30.   Whether or not the assassins were acting to prevent a diplomatic breakthrough on Nagorno-Karabakh, their action has made such a breakthrough more difficult.