数字用户线路接入种类很多，其中非对称数字用户线是(43)。光纤接入网有多种，其中(44)是最理想的。

单项选择题下列程序执行后的结果是______。 package ch1; import java.io.*; public class ex22 { static, String filename = 'ch1 kfile22.txt'; public static void main(String[] args) { try { FileWriter fr = new FileWriter(filename); PrintWriter pr = new PrintWriter(fr); String name = 'xiaoming'; String phone = '123456'; String age = '12'; pr.println(name + ',' + phone + ',' + age); pr.close(); fr.close(); } catch(IOException ioe) { ioe.printStackTrace() } } }

单项选择题以下选项中不采用组播协议的应用是(125)。在IPV4地址中，(126)类地址作为组播地址。

单项选择题下列复用方式中，(112)是光纤通信中使用的复用方式，EI载波把32个信道按(113)方式复用在一条2.048Mb s的高速信道上，每条话音信道的数据速率是(114)。

单项选择题(接上一题)该点与计划S曲线的水平距离表示(70)。

单项选择题Personal firewall is a technology that helps(66)intruders from accessing data on your PC via the Internet or another network, by keeping(67)data from entering or exiting your system.Hackers do not just target national security organizations for(68): They want your tax returns, network passwords, or bank account numbers. And you do not want the FBI kicking in your door because someone hijacked your PC to(69)in the latest denial-of-service attack on the Internet. Now that 'always-on' broadband connections such as cable modems and digital subscriber line are becoming more popular, home users are at risk. Fortunately, you can protect your data. Firewalls can block(70)attacks and protect your PC from outside threats.

单项选择题data effectively is crucial for success in today's competitive environment. Managers must know how to use a variety of tools. Integrated data takes information from different sources and puts it together in a meaningful and useful way. One of the difficulties of this is the(72)in hardware and software.(73)integration uses a base document that contains copies of other objects.(74)integration uses a base document that contains the current or most recent version of the source document it contains.(75)provides an overview of the program written in' plain' English, without the computer syntax.

单项选择题将十进制数-0.3125化成定点二进制补码表示的小数是(5)。将该数表示成二进制浮点规格化数，其阶码3位，尾数5位(均含1位符号)，都用补码表示，该浮点数是(6)。

单项选择题由6个字符的7位ASCII编码排列，再加上水平垂直奇偶校验位构成下列矩阵(最后一列为水平奇偶校验位，最后一行为垂直奇偶校验位)。字符：则X1X2X3X4处的比特分别为(7)；X5X6X7X8处的比特分别为(8)；X9X10X11X12处的比特分别为(9)。

单项选择题Traditional structured analysis techniques focus upon the flow of(71)within a system. Object - oriented analysis emphasizes the building of real - world models. It examines requirements from the perspective of the classes and objects found in the vocabulary of the(72)domain.Traditional system design method emphasizes the proper and effective structure of a complex system. Object -oriented design method encompasses the process of object -oriented decomposition and a(73)for depicting both logical and physical as well as static and dynamic models of the system under design.Object - oriented programming is a method of implementation in which programs are organized as cooperative collections of objects, each of which represents an(74)of some class, and whose classes are all members of a hierarchy of classes united via(75)relationships.

单项选择题FDDI的基本编码方法是(26)。在此基础上采用(27)，编码以获得足够的同步信息，这样使编码效率提高到(28)。IEEE 802.3所采用的编码方式是(29)，编码效率是(30)。