一台PC计算机系统启动时，首先执行的是(42)，然后加载(43)。在设备管理中，虚拟设备的引入和实现是为了充分利用设备，提高系统效率，采用(44)来模拟低速设备(输入机或打印机)的工作。

 已知A、B的值及表达式A²/(5A+B)的求值过程，且A、B已赋值，则该公式的求值过程可用前驱图(45)来表示，若用P-V操作控制求值过程，需要(46)的信号量。

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  Remote administration types are an example of one kind of(71)malicious software, the Trojan horse, or more simply Trojan. The purpose of these programs isn't replication,(72)to penetrate and control. That masquerade as one thing when in fact they are something else, usually something destructive. There are a number of kinds of Trojans, including spybots, (73) report on the Web sites a computer user visits, and keybots or keyloggers, which record and report the user's keystrokes in order to discover passwords and other confidential information.

 RATS attempt to give a remote intruder administrative control of an infected computer. They work as(74)pairs. The server resides on the infected machine, while the client resides elsewhere, across the network, where it's available to a remote intruder. Using standard TCP/IP or UDP protocols, the client sends instructions to the server. The server does(75) it's told to do on the infected computer.

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现需要一个32M×8规格的存储器，现只有规格为1M×8的存储器芯片，则需要(49)个这样的存储器芯片。存储芯片的地址长度需要(50)位，主存储器的地址长度需要(51)位。

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