Task 1 A -- screen saver B -- log on/log in C -- hacker D -- virus E -- blog F -- click rate G -- page view H -- bug I -- voice and video chat J -- gateway K-- BBS (Bulletin Board System) /forum L- submit post M -- search engine N -- refresh O -- security certificate P -- firewall Q -- server R -- browser ( ) 屏幕保护 ( ) 刷新