病毒的种类有哪些？主要有两种病毒：shell病毒和instrusive病毒。Shell病毒把自己盘绕在主程序周围，它并不修改原程序。这种病毒容易复制因此它的数量占了所有病毒的一半。Instrusive病毒入侵现有程序并且把自己的一部分插入主程序。这种病毒不易复制，但是很难在不损伤主程序的情况下被删除。

　　重点单词：

　　1、virus 病毒

　　2、outcome 结果

　　例句: I think there can be but one outcome to this affair.

　　我认为这件事只能有一种结局。

　　3、program [电脑]程序

　　4、replicate 复制，折叠，复制品

　　5、host [电脑]主机

　　6、at some point 某时, 某种情况下

　　7、so-called 所谓的

　　8、malignant 邪恶的，极有害的

　　9、data 数据

　　10、wipe out 消灭；彻底摧毁

　　例句: They have wipe out the enemy's major military target.

　　他们已经彻底摧毁了敌人的主要军事目标。

　　句型分析:

　　1、The cause(of the term computer virus)is the likeness(between the biological virus and the evil program [infected with computers].)

　　2、The timing(of the attack)can be linked to a number(of situations), including [1]a certain time or date, [2]the presence of a particular file, [3]the security privilege level of the user, [4]and the number of times a file is used.

　　[1]、[2]、[3]、[4]是在including下的并列短句。
　使用不健康网络可能有损心理健康

　　Internet use appears to cause a decline in psychological well-being,according to research at Carnegie Mellon University.

　　Even people who spent just a few hours a week on the Internet experienced more depression and loneliness than those who logged on less frequently, the two-year study showed. And it wasn't that people who were already feeling bad spent more time on the Internet, but that using the Net actually appeared to cause the bad feelings.

　　Researchers are puzzling over the results, which were completely contrary to their expectations. They expected that the Net would prove socially healthier than television, since the Net allows users to choose their information and to communicate with others.

　　The fact that Internet use reduces time available for family and friends may account for the drop in well-being, researchers hypothesized. Faceless, bodiless virtual communication may be less psychologically satisfying than actual conversation, and the relationships formed through it may be shallower. Another possibility is that exposure to the wider world via the Net makes users less satisfied with their lives.

　　But it's important to remember this is not about the technology; it's about how it is used, says psychologist Christine Riley of Intel, one of the study's sponsors. It really points to the need for considering social factors in terms of how you design applications and services for technology.

　　参考译文：

　　根据卡内基麦伦大学的研究，使用因特网可能会导致心理健康程度下降。

　　两年的研究表明，上网次数多的人与较少的人相比，即使是一周仅上网几小时也会经常地感觉到沮丧和孤独。这不是说已经有不良感觉的人在网上花费了更多的时间，而是说使用因特网似乎确实诱发了人们的不良感觉。