11.   I ran into my colleague Judy Miller, a bioterrorism expert, and asked if we should be worried about smallpox, camel pox and mouse pox.

12.   If the hijackers did have anthrax, they would probably have needed an accomplice to mail the tainted letters, said bioterrorism experts knowledgeable about the case.

13.   If the hijackers did have anthrax, they probably would have needed an accomplice to mail the tainted letters, according to bioterrorism experts knowledgeable about the case.

14.   It is considered among the gravest terrorist threats because of its high lethality, but bioterrorism experts believe it is an unlikely agent because of its rarity.

15.   She was watching an interview with a bioterrorism expert when the interviewee emphasized the importance of medical professionals being aware of the symptoms.

16.   Some bioterrorism experts have also raised the possibility that mail sorting could explain the smaller size of the clumps of spores in the Leahy anthrax.

17.   Thomas Inglesby, a bioterrorism expert at the Johns Hopkins University Center for Civilian Biodefense Studies, said his group strongly recommended that exposed people take the vaccine.

18.   And in telephone interviews, bioterrorism experts agreed.

19.   But bioterrorism experts have said in recent months they believe the virus has been distributed to other spots in Russia, perhaps in places with less effective security controls.

20.   But bioterrorism experts worry that the virus could be obtained by terrorists and intentionally released in the general population.