1.   And yet, say bioterrorism experts, areas of the country remain extraordinarily unprotected if a terrorist strikes.

2.   A federal agent and bioterrorism expert said there was no evidence that the anthrax, described as pure spores by Parker, came from a weapons program.

3.   Bush administration bioterrorism experts remain befuddled by the origin of the anthrax.

4.   But as the nation builds its bioterrorism defenses, Amy Smithson, a bioterrorism expert at the Henry L. Stimson Center, predicted the scares would only increase.

5.   But some bioterrorism experts suspect that other nations have access to the virus and have been using it to plan biological warfare.

6.   But on Sunday, bioterrorism experts said that no unusual precautions are recommended for suspected anthrax contamination.

7.   Delivering the drugs into the hands of people who need them is another significant challenge, according to public health officials and bioterrorism experts.

8.   Dr. Michael Osterholm, a bioterrorism expert at the University of Minnesota, said it was important for investigators to keep their minds open to all possibilities.

9.   Even so, bioterrorism experts welcomed the groundings of crop dusters.

10.   Henderson, the Johns Hopkins bioterrorism expert, said prevention and treatment efforts are lagging badly.