1.   Investigators have repeatedly failed to find evidence of foreign involvement in the letter attacks.

2.   The bad news is that the letter attacks are small stuff compared to possible future threats, experts on biological weapons warn.

3.   Anthrax scares became daily events in Britain last month after a wave of letter attacks hit the United States.

4.   Anthrax scares have become daily events in Britain since a wave of letter attacks hit the United States this month.

5.   Federal health officials expressed cautious optimism Tuesday that the worst of the letter attacks may be over.

6.   Greendale School was the phony return address used in the anthrax letter attacks.

7.   In October last year, anthrax scares became daily events in Britain after a wave of letter attacks hit the United States.

8.   The anthrax used in letter attacks appears to have been produced in the United States, the White House says, but who mailed it remains a mystery.