Board logo

标题: 四级练习2016.03.23 [打印本页]

作者: Rebecca949    时间: 2016-3-25 09:15     标题: 四级练习2016.03.23

[audio]http://sound.yywz123.com/tingbbs/cet4/cet420160323.mp3[/audio]


The computer virus is an outcome of the computer overgrowth in the 1980s. (1)__________________________________________________.The origin of this term came from an American science fiction "The Adolescence of P-1" written by Thomas J. Ryan, published in 1977. Human viruses invade a living cell and turn it into a factory for manufacturing viruses. However, computer viruses are small programs. They expand by attaching a copy of themselves to another program. Once attached to the host program, the viruses then look for other programs to "infect". (2)_________________________________.The timing of the attack can be linked to a number of situations, including a certain time or date, the presence of a particular file, the security level of the user, and the number of times a file is used. Likewise, the mode of attack varies. So called "benign" or the harmless viruses might simply display a message, like the one that infected IBM's main computer system last Christmas with a season's greeting.(3)______________________________________________.The attack is to wipe out data, to delete files, or to format the hard disk.



本帖隐藏的内容需要回复才可以浏览





欢迎光临 英语听力论坛 (http://bbs.tingroom.com/) Powered by Discuz! 7.2