1.   At the same time, a suspicious letter with a powdery white substance forced the New York Times offices closed and a third-floor newsroom emptied.

2.   Boston authorities are fielding scores of calls each day from people concerned about suspicious letters of packages, Police Commissioner Paul Evans said in Washington.

3.   --A Brazilian laboratory said Saturday said that a suspicious letter sent to the Rio de Janeiro bureau of The New York Times tested negative for anthrax.

4.   A spokesman for the District of Columbia Fire and Emergency Medical Services team said that a suspicious letter was reported by ABC employees in their mailroom.

5.   Abortion clinics in Stuart, Boca Raton, Fort Lauderdale and Pembroke Pines have all received suspicious powdery letters this week, according to Planned Parenthood.

6.   After it is sorted by the postal inspectors, he said, unsuspicious mail will be delivered, and suspicious letters and packages will be set aside for scrutiny.

7.   But the search for suspicious letters quickly expanded beyond the Florida post offices.

8.   But they could find no record of suspicious letters to her, said Dr. David L. Swerdlow, a CDC epidemiologist involved in the work.

9.   But with suspicious letters now appearing around the country, there are still doubts about how effectively the system deals with bioterrorism threats.

10.   Even so, a backlog has developed, with people sometimes waiting several days to learn whether their suspicious letters contained anthrax.