单项选择题 Which of the following protocols uses port 443 by default?（）

单项选择题 A user has discovered that even though they are using the latest version of the anti-virus software,the computer is still being infected by a virus. Which of the following is the BEST solution for this problem?（）

多项选择题 Operating system files for Windows Vista and Windows XP are located in which of the following?（）(Select TWO).