20. ( ), software used in corporate networks (intranets and extranets) to prevent unauthorized people from accessing the network. A. Firewall B. Modem C. Hypertext D. TCP ...

15. ( ), difference between the lowest and highest frequencies transmitted in a particular channel or system. A. Amplitude B. Bandwidth C. Bridge D. Network ...

10. ( ) also called a program, is the series of computer language coded instructions that tells the computer how to perform tasks. A. Software B. Hardware C. Compiler D. Interpreter ...

5. Linux is an operating system similar to ( ) that is becoming more and more popular. A. Windows 98 B. Windows 2000 C. Windows XP D. Unix ...

10. Operating system is a set of programs that perform specific tasks for users.( ) A. 错误 B. 正确 ...

5. Gateway, interface that enables dissimilar networks to communicate with one another.( ) A. 错误 B. 正确 ...

20. ( ) performs arithmetic, comparison, and logic operations. It is one part of the CPU. A. RAM B. ROM C. CPU D. ALU ...

15. ( ) is one of the components of the CPU, tells the rest of the computer system how to carry out a program's instructions. A. Control unit B. ALU C. RAM D. ROM ...

10. A ( ) is the primary input device. It is used for entering letters, numbers and commands into the system. A. RAM B. keyboard C. output devices D. memory ...

5. ( ) can be in the form of programs, commands and user responses. A. Processor B. Instructions C. Mouse D. Port ...