单项选择题

The Internet is an open system,and most information is available to everyone.It is very important to add（）to existing system for protecting the secret information.

A．Web pages
B．modem
C．security
D．network

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单项选择题
C++ fully supports（）programming.

A．visual
B．object-oriented
C．logic
D．natural language
单项选择题
The（）is a collection of modules serving as interface between hardware and software to provide a software platform.

A．computer
B．processor
C．application software
D．operating system
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