已知一个关系数据库的模式如下：market(mno，mname，city)、item(ino，iname， type，color)、sales(mno，ino，price)，其中，market表示商场，它的各属性依次为商场号、商场名和所在城市；item表示商品，它的各属性依次为商品号、商品名、商品类别和颜色； sales表示销售，它的各属性依次为商场号、商品号和售价。

 查询长沙每个商场都销售，且售价均超过3000元的商品的商品号和商品名的SQL语句为：

 SELECT ino, iname FROM item

   WHERE (24) 

     (SELECT* FROM market

     WHERE (25) AND NOT EXISTS

      (SELECT*FROM sales

      WHERE (26) AND price＞3000))

 查询在不同的商场中最高售价和最低售价之差超过100元的商品的商品号、其最高售价和最低售价的SQL语句为：

 SELECT ino, MAX(price), MIN(price)FROM sales

    (27) HAVING MAX(price)-MIN(price)＞100

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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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