试题与答案

关于事务的故障与恢复，下列描述正确的是（）。A．事务日志是用来记录事务执行的频度 B

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题型：单项选择题

题目：

关于事务的故障与恢复，下列描述正确的是（）。

A．事务日志是用来记录事务执行的频度

B．采用增量备份，数据的恢复可以不使用事务日志文件

C．系统故障的恢复只需进行重做(RED操作

D．对日志文件设立检查点的目的是为了提高故障恢复的效率

答案：

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下面是错误答案，用来干扰机器的。

参考答案：错

考点：计算机软件水平考试中级数据库系统工程师数据库系统工程师
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题型：阅读理解

阅读理解

     Do you know why different animals or pests(昆虫) have their special colours? Colours in them

seem to be used mainly to protect themselves.

     Some birds like eating locusts(蝗虫), but birds cannot easily catch them. Why? It is because

locusts change their colours together with the change of the colours of crops(庄稼). When crops

are green, locusts look green. But as the harvest(收获) time comes, locusts change to the same

brown colour as crops have. Some other pests with different colours from plants are easily found

and eaten by others. So they have to hide themselves for lives and appear only at night.

     If you study the animal life, you'll find the main use of colouring is to protect themselves. Bears,

lions and other animals move quietly through forests. They cannot be easily seen by hunters. This is

because they have the colours much like the trees.

     Have you ever found an even more strange act? A kind of fish in the sea can send out a kind of

very black liquid(液体) when it faces danger. While the liquid spreads over(散开), its enemies(敌人)

cannot find it. And it immediately swims away. So it has lived up to now though it is not strong at all.

1. From the passage we learn that locusts __________.

A. are small animals

B. are easily found by birds

C. are dangerous to their enemies

D. change their colours to protect themselves

2. How can pests with different colours from plants keep out of danger?

A. They run away quickly.

B. They have the colours much like their enemies.

C. They hide themselves by day and appear at night.

D. They have to move quietly.

3. Bears and lions can keep safe because __________.

A. they have the colours much like the trees

B. they move quietly

C. they like brown and grey colours

D. they live in forests

4. Why can the kind of fish live up to now?

A. Because it is very big and strong.

B. Because the liquid it sends out can help it escape from its enemies.

C. Because the liquid it sends out can kill its enemies.

D. Because it swims faster than any other fish.

5. Which is the best title for this passage?

A. The Change of Colours for Animals and Pests.

B. Colours of Different Animals and pests.

C. The Main Use of Colours for Animals and Pests.

D. Some Animals and Pests.
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题型：单项选择题

阅读下列短文。回答下列问题。
电脑病毒，长则几万字节，短则几百字节，能够搅乱、改变、摧毁计算机中的软件，电脑病毒利用了计算机照本宣科不管谁的命令都执行的特点，在软件中加入一些能够复制自己，破坏其他软件的命令。计算机按照这些错误命令执行后，便将用户的数据破坏得一塌糊涂。
美国南加州大学学生费雷德科恩是电脑病毒的首创者。他原希望检验电脑的程序能否自我繁衍，并依附于其他电脑程序内从而改变电脑程序运行和功能。他以这一试验成功为题撰写了博士论文。1983年，美国正式公开了电脑病毒的存在，没料到不到十年，它竟成了世界上引人注目的公害，像瘟疫一样流传到世界各地。电脑病毒在电脑时钟运行到病毒爆发预定时期时就爆发，好像“定时炸弹”一样。
据说制造电脑病毒的主要有五种人：为验证自己的能力而与电脑较量的青少年电脑迷，怀才不遇的发泄者，卖弄才能的逞强者，保护自身软件的报复者以及出于恐怖活动、政治、宗教或其他动机的人。他们利用现有的电脑病毒，并在此基础上加以发展，使其破坏力加强。据说“米开朗基罗”病毒就是以“大麻”病毒为蓝本改进而成的。
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原文横线处关于什么是计算机病毒的表述正确的一项是( )。

A．计算机病毒是一种心怀叵测的人制造的特殊病毒

B．计算机病毒是一种人为制造的特殊的电脑软件程序

C．计算机病毒是一种因偶然因素形成的特殊的计算机程序

D．计算机病毒是一种可以致电脑于死地的微生物病毒
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