数据传送操作过程中由于磁头损坏或故障造成磁盘块上的内容丢失。这类故障属于( )。

题型:单项选择题

问题:

数据传送操作过程中由于磁头损坏或故障造成磁盘块上的内容丢失。这类故障属于( )。

A.系统故障

B.磁盘故障

C.逻辑错误

D.硬件故障

考点:计算机等级考试数据库技术计算机三级(数据库技术)21
题型:单项选择题

采用净现值(NPV)、内部收益率(IRR)和差额内部收益率(△IRR)进行互斥方案比选,它们的评价结论是:().

A.NPV和△IRR总是不一致的

B.IRR和△IRR总是一致的

C.NPV和△IRR总是一致的

D.NPV、IRR和△IRR总是一致的

题型:单项选择题

阅读理解

     Flags have existed for over 3000 years. The earliest flags were wooden or metal poles topped with

a carving(雕刻品). About 2000 years ago pieces of fabric were added to some poles for decoration.

Over the next 500 years the free-flying part of the flag became more important.

     Every country today has its own flag. Many groups and organizations also have a flag which stands

for, or symbolizes, the aims of the group.

     The UN flag depicts (描绘)a world map, centered on the north pole. The map is surrounded by an

olive(橄榄)wreath(花环)symbolizing peace and co-operation. The flag is blue and white.

1. Flags have been in existence for ____    

A.500 years

B. more than 3000 years

C. about 2000 years

D. between 500 and 2000 years

2. A very old flag is likely to _____.

A. be made of fabric

B. have a map on it

C. have white shapes on it

D. be made of carved wood

3. An olive wreath is used to represent_______ .

A. peace

B. purity    

C. justice

D. equality

题型:单项选择题

证券公司从事中间介绍业务,不得()。

Ⅰ.协助办理开户手续

Ⅱ.代理客户进行期货交易、结算或者交割

Ⅲ.代期货公司、客户收付期货保证金

Ⅳ.利用证券资金账户为客户存取、划转期货保证金

A.Ⅱ、Ⅲ、Ⅳ

B.Ⅰ、Ⅱ、Ⅲ

C.Ⅰ、Ⅱ、Ⅳ

D.Ⅰ、Ⅲ、Ⅳ

题型:单项选择题

双宿主网关系统逻辑框图如下图所示,仔细阅读,然后回答下列问题:

简述双宿主网关的工作原理。

题型:单项选择题

照射野的半影区,指的是()

A、剂量对称区域

B、剂量变化快的区域

C、剂量波动区域

D、照射野内剂量变化的区域

E、照射野边缘剂量递减的区域

更多题库