问题 单项选择题

下列有关计算机病毒特点的表述中,错误的是()。

A.如果不经过代码分析,病毒程序与正常程序是不容易区别开来的

B.病毒程序能使自身的代码强行传染到一切符合其传染条件的未受感染的程序上

C.大部分病毒感染系统之后一般不会马上发作

D.有些病毒侵入系统后,不会对系统和应用程序产生任何影响

答案

参考答案:D

解析:计算机病毒在侵入正常的计算机系统后,其破坏性不一定马上表现出来,暂时不对系统产生影响。但是一旦条件成熟,或者满足特定的触发条件时才发作,最终对系统产生影响。

单项选择题
阅读理解

  As the proverb says,“No one knows the value of health until he loses it.”In other words, nothing is more valuable than health.

  It is clear that health is the foundation(基础) of one's future success. If you become sick, it is scarcely possible to pursue(从事) your career effectively, much less make your dreams come true. On the other hand, if you are strong, you can go all out to overcome the obstacles(障碍) that lie ahead of you.

  Health is the resource of our energy. What should we do to maintain(保持) our health? First we should exercise every day to strengthen our muscles. Second, we might as well keep good hours. If we get up early, we can breathe fresh air and see the sunrise. This habit can do wonders for our outlook on life. Third, there is a proverb that says,“Prevention is better than cure.”If you pay close attention to your health, you can avoid getting sick, or at least cure yourself of a disease while it is still in its beginning stage.

  In conclusion, health is more important than wealth. Those who are rich but poor in health are no more fortunate than those who are poor, and healthy in body. If you want your wish to come true, health is the most important component(组成部分) of your success.

  57.A man knows the value of health _____.

 A.till he loses B.before he loses it C.after he loses it D.when he doesn't lose it

 58.In the second paragraph,“go all out to”means _____.

 A.go yourself outside to B.try very hard to C.go with your friends to D.save your energy to

 59.In the third paragraph, the topic sentence is _____.

  A.Health is the resource of our energy  B.Prevention is better than cure

  C.We might as well keep good hours  D.This habit can do wonders for our outlook on life

 60.“Those who are rich but poor in health are no more fortunate than those who are poor, and healthy in body”this sentence is understood as “_____”.

  A.Those who are rich but poor in health are less fortunate than those who are poor, and healthy in body.

  B.Those who are rich but poor in health are as fortunate as those who are poor, and healthy in body.

  C.Those who are rich but poor in health are not more fortunate than those who are poor, and healthy in body.

D.Those who are rich but poor in health are as unfortunate as those who are poor, and healthy in body.