多项选择题
A. block extension list
B. block MIME type
C. protocol command list
D. notifications-options
单项选择题 Using a policy with the policy-rematch flag enabled, what happens to the existing and new sessions when you change the policy action from permit to deny?（）
单项选择题 Which statement is true when express AV detects a virus in TCP session?（）
单项选择题 Which CLI command provides a summary of what the content-filtering engine has blocked?（）