試題1

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試題2

E-R圖轉(zhuǎn)換為關(guān)系模型時(shí)，對(duì)于實(shí)體E1與E2間的多對(duì)多聯(lián)系，應(yīng)該將( )。
A．E₁的碼加上聯(lián)系上的屬性并入E₂
B．E₁的碼加上聯(lián)系上的屬性獨(dú)立構(gòu)成一個(gè)關(guān)系模式
C．E₂的碼加上聯(lián)系上的屬性獨(dú)立構(gòu)成一個(gè)關(guān)系模式
D．E₁與E₂碼加上聯(lián)系上的屬性獨(dú)立構(gòu)成一個(gè)關(guān)系模式

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試題3

某系統(tǒng)的可靠性結(jié)構(gòu)框圖如下圖所示。該系統(tǒng)由4個(gè)部件組成，其中2、3兩部件并聯(lián)冗余，再與1、4部件串聯(lián)構(gòu)成。假設(shè)部件1、2、3的可靠度分別為0.90、0.70、0.70。若要求該系統(tǒng)的可靠度不低于0.75，則進(jìn)行系統(tǒng)設(shè)計(jì)時(shí)，分配給部件4的可靠度至少應(yīng)為 （ ） 。

A. A
B. B
C. C
D. D

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試題4

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試題5

設(shè)元素序列a、b、c、d、e.f經(jīng)過(guò)初始為空的棧S后，得到出棧序列cedfba，則棧S的最小容量為( )。
A．3
B．4
C．5
D．6

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試題6

In the fields of physical security and information security, access contro lis the selective restriction of access to a place orothe rresource. The act of accessing may mean consuming, entering, or using. Permission to access a resource is called authorization（授權(quán)）．
An access control mechanism(1) between a user (or a process executing on behalf of a user) and system resources, such as applications,operating systems,firewalls,routers,files,and databases.The system must first a uthenticate（驗(yàn)證）a user seeking access.Typically the authentication function determines whether the user is（2 ）to access the system at all. Then the access control function determines if the specific requested access by this user is permitteD. A security administrator maintains an authorization database that specifies what type of access to which resources is allowed for this user. The access control function consults this database to determine whether to（3 ）access. An auditing function monitors and keeps a record of user accesses to system resources.
In practice,a number of（4 ）may cooperatively share the access control function. All operating systems have at least arudimentary（基本的）,and in many cases aquite robust,access control component.Add-on security packages can add to the（5 ）access control capabilities of the OS. Particular applications orutilities, such as a database management system, also incorporate access control functions. External devices,such as firewalls, can also provide access control services.
（1）A．cooperates
B．coordinates
C．connects
D．mediates
（2）A．denied
B．permitted
C．prohibited
D．rejected
（3）A．open
B．monitor
C．grant
D．seek
（4）A．components
B．users
C．mechanisms
D．a(chǎn)lgorithms
（5）A．remote
B．native
C．controlled
D．Automated

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試題7

內(nèi)存單元按字節(jié)編址，地址0000A000H～0000BFFFH共有( )個(gè)存儲(chǔ)單元。
A．8192K
B．1024K
C．13K
D．8K

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試題8

在UNIX操作系統(tǒng)中，若用戶鍵入的命令參數(shù)的個(gè)數(shù)為1時(shí)，執(zhí)行cat$1命令；若用戶鍵入的命令參數(shù)的個(gè)數(shù)為2時(shí)，執(zhí)行cat>>$2<$1命令。請(qǐng)將下面所示的Shell程序的空缺部分補(bǔ)齊。
case（ ）in
1)cat$1;;
2)cat>>$2<$1;;
*)echo 'default...'
esac
A、$$ 
B、$@ 
C、$# 
D、$* 

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試題9

某項(xiàng)目的活動(dòng)持續(xù)時(shí)間及其依賴關(guān)系如下表所示，則完成該項(xiàng)目的最少時(shí)間為（ ）天。

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試題10

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