问题 单项选择题

互联网给人类带来极大便利。但是,1988年美国国防部的计算机主控中心遭黑客人侵,6千台计算机无法正常运行。2002年,美军组建了世界上第一支由电脑专家和黑客组成的网络部队。2008年,俄罗斯在对格鲁吉亚采取军事行动之前,先攻击格鲁吉亚的互联网,使其政府、交通、通讯、媒体、金融服务业陷入瘫痪。由此可见,______。
以下哪一项陈述可以最合逻辑地完成上文的论述( )

A.网络已经成为世界各国赖以正常运转的“神经系统”
B.在未来战争中,网络战可能成为一种新的战争形式
C.世界各国的网络系统都可能存在着安全漏洞
D.及时对杀毒软件进行升级.可以最大限度地防范来自网络的病毒

答案

参考答案:B

解析: 结论型题目。题干举了三个例子说明了互联网的存在使网络战成为可能,B项正确。由题干只可知网络会对一些行业造成影响,但不足以推出网络已经成为世界各国赖以正常运转的“神经系统”,A项错误;C项不是题干举例所要得出的结论;D项是无关项。

阅读理解

Ⅲ. 阅读(共两节,满分40分)

第一节 阅读理解(共15小题;每小题2分,满分30分)

阅读下面短文,掌握其大意,然后从41—55各题所给的四个选项(A、B、C、D)中,选出最佳选项,并在答题卡上将该项涂黑。

Although April did not bring us the rains we all hoped for, and although the Central Valley doesn’t generally experience the sound and lightning that can go with those rains, it’s still important for parents to be able to answer the youthful questions about thunder and lightning.

The reason these two wonders of nature are so difficult for many adults to explain to children is that they are not very well understood by adults themselves. For example, do you know that the lightning we see flashing down to the earth from a cloud is actually flashing up to a cloud from the earth? Our eyes trick us into thinking we see a downward motion when it’s actually the other way round. But then, if we believed only what we think and we see, we’d still insist that the sun rises in the morning and sets at night.

Most lightning flashes take place inside a cloud, and only a relative few can be seen jumping between two clouds or between earth and a cloud. But, with about 2,000 thunderstorms taking place above the earth every minute of the day and night, there’s enough activity to produce about 100 lightning strikes on earth every second.

Parents can use thunder and lightning to help their children learn more about the world around them. When children understand that the light of lightning flashing reaches their eyes almost at the same moment, but the sound of the thunder takes about 5 seconds to travel just one mile, they can begin to time the interval(间隔) between the flash and the crash to learn how close they are to the actual spark(闪光).

1. According to the author, in the area of the Central Valley, ___________.

A. rains usually come without thunder and lightning

B. it is usually dry in April

C. children pay no attention to the two natural wonders

D. parents are not interested in thunder and lightning

2. We believe that lightning is a downward motion because ___________.

A. we were taught so by our parents from our childhood

B. we are taken in by our sense of vision

C. it is a common natural sight

D. it is a truth proved by science

3. What is TRUE about lightning according to the passage?

A. Only a small number of lightning flashes occur on earth.

B. Lightning travels 5 times faster than thunder.

C. Lightning flashes usually jump from one cloud to another.

D. There are far more lightning strikes occurring on earth than we can imagine.

4. The underlined word “activity” is most closely related to the word(s)___________.

A. “cloud”                                       B. “lightning strikes”        

C. “lightning flashes”                              D. “thunderstorms”

5. It can be concluded from the passage that____________.

A. we should not believe what we see or hear

B. things moving downward are more noticeable

C. people often have wrong ideas about ordinary phenomena (现象)

D. adults are not as good as children in observing certain natural phenomena

多项选择题